Green Chemistry Blog

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on the chemical valorisation of biomass derived furanics and carboxylic acids over niobium-based catalysts (DOI: 10.1039/D4GC00207E).

Read our interview with Margarida M. Antunes, one of the corresponding authors.

Could you briefly explain the focus of your article to the non-specialist (in two or three sentences only)?

Our group wishes to contribute to a greener world by developing sustainable alternatives to fossil fuels using renewable and cheap sources of energy, which can be, for example, available biomass derived waste (e.g., forestry, agricultural or food waste). The main components of vegetable biomass include carbohydrates. Before using this available waste and convert it to green (biobased) products, it is important to investigate the chemical reactions involved. In this work, we investigated the conversion of furfural (which is an industrial platform chemical derived from carbohydrates) to drop-in-fuels, using relatively cheap and green catalysts.

How would you set this article in a wider context?

Niobium based oxides are known to have a lot of advantages, such as water-tolerance. This is very important since water is a co-product of the biomass conversion processes we intend to explore. Moreover, they possess Brønsted and Lewis acidity required for these conversion processes and have shown superior catalytic performance in relation to other metal oxides.

In collaboration with Dr Nicola Pinna and Dr Patrícia Russo (Humboldt University Berlin), niobium oxide nanoparticles embedded in a mesoporous silica matrix were synthesised by a relatively simple methodology. Our group investigated the catalytic properties. The prepared materials were stable in recycling runs in various reactions, such as for the aldol condensation of furfural with acetone, and for esterification reactions of alpha-angelica lactone, levulinic and valeric acid, which are all furfural derivatives. Moreover, they showed high acetone and ethanol consumption efficiency, which is important for an integrated biorefinery concept and sustainability.

What is the motivation behind this work?

Our group enjoys the fascinating field of Catalysis, which is crucial to the Chemical Industry. We explore selective and stable catalysts to efficiently promote target chemical reactions under moderate conditions, which may lead to more sustainable processes.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

It was exciting to realize that indeed the niobium oxide nanoparticles embedded in a mesoporous silica (especially SiNb42 and SiNb75) could significantly increase the selectivity towards our main product, 4-(furan-2-yl)but-3-en-2-one (C8), in relation to the niobia nanomaterial Nb₂O₅, or in relation to a commercial micro Nb₂O₅ (which led to sluggish results) or yet in relation to a Nb₂O₅/TUD-1 composite using an equivalent atomic amount of Nb, prepared by embedding the Nb₂O₅ nanoparticles in a mesoporous TUD-1 type silica. Moreover, the Nb₂O₅ alone were partially deactivated in recycling runs, albeit when embedded in a mesoporous silica (using silica tetrachloride), their stability was enhanced. However, for Nb₂O₅/TUD-1 there was observed deactivation. The reasons for such behaviour are still not clear. The inherent properties of each material play an important role in their catalytic performance.

What is the next step? What work is planned?

Our next step is trying to use waste biomass sources instead of model substrates by using the acquired knowledge. This is of course a challenge, but we hope to count on the collaboration of scientists from the academia and industry, attempting to come closer to practical application.

Please describe your journey to becoming part of the Green Chemistry community

Since I integrated the associated laboratory CICECO, at the University of Aveiro, in 2008, I have been engaged in developing research work in the field of catalysis, with a mindset on sustainability and Green Chemistry. Developing research with this mindset is a reason for feeling proud.

Why did you choose to publish in Green Chemistry?

Green Chemistry is a prestigious journal, internationally recognised and read by many scientists, and valorises research that aims to reduce the environmental impact associated with the chemistry industry. In this sense, we thought that Green Chemistry was the best choice for our manuscript.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

During the last 25 years, the Green Chemistry journal has evolved according to the demands for sustainability. Several reviews and perspective papers have been discussed concerning the use of greener alternatives for fossil fuels. Environmental issues and sustainable solutions have been debated through life cycle assessment studies and techno economic studies. Some studies are promising and reliable experimentally, but the costs of the processes are still high. Sustainable processes for producing biofuels and biobased chemicals continues to demand much investigation. In the coming years, the way of use of fossil fuels and the supply chains should be rethought, which calls for the Green Chemistry community.

Meet the corresponding author

Margarida M. Antunes received a Licentiate degree in Industrial Chemistry from the University of Coimbra, Portugal, in 2004, where she studied the polymorphism of erythritol and threitol using differential scanning calorimetry and thermomicroscopy. In 2008, she earned a Master´s degree in Chemistry of Natural Products from the University of Aveiro (UA), where she synthesised and characterised pharmaceutical compounds. Margarida proceeded to doctoral studies at the UA, having concluded her PhD thesis in 2012, on the conversion of polysaccharides to furanic derivatives using either ionic liquids or heterogeneous acid catalysts. In the same year, she was awarded a post-doc grant from the FCT (Portuguese Foundation for Science and Technology) and in 2019 she became researcher at the UA, CICECO – Aveiro Institute of Materials. She investigates the catalytic conversion of several types of biomass derivatives to valuable bio-based products via heterogeneous catalytic routes. For example, D-fructose for food and non-food applications, fuel blends synthesised via condensation between biomass derived compounds (e.g. furfural) and glycerol, and gamma-valerolactone which is a promising fuel additive and intermediate for transportation fuels. She develops multifunctional heterogeneous catalysts to carry out multiple reactions (e.g. acid and reduction) in one-pot synthesis strategies. The heterogeneous catalysts include bimetallic, micro- and mesoporous materials prepared via different procedures, such as hydrothermal syntheses and top-down modifications (leading to hierarchical materials). Besides developing catalysts, Margarida is concerned about the energy efficiency of processes and has investigated different energy supply methods. One of her strong motivations is to study the sustainable repurposing of undesirable waste biomass sources to drop-in-fuels with reduced CO2 emissions compared to fossil fuels, via different catalytic strategies.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on the use of dipyridyldithiocarbonate (DPDTC) as an environmentally responsible reagent leading to esters and thioesters under green chemistry conditions (DOI: 10.1039/D3GC03093H)

Read our interview with Prof. Bruce H. Lipshutz, the corresponding author.

Could you briefly explain the focus of your article to the non-specialist?

This article focuses on developing technology for making fundamental bonds that follow Nature’s lead; that is, using the same types of intermediates used throughout evolution, and as witnessed today in the human body to arrive at these same important bond constructions. This green approach can be used by the pharmaceutical industry in making their drugs, as it provides an alternative that does not use organic solvents that deplete limited petroleum reserves, nor does it create waste. Thus, the major difference between existing methodologies and the one described in this paper is that prior art utilizes reagents that are waste-generating, and organic solvents that are flammable and toxic as the reaction medium, neither being recycled. This technology, however, relies on either no solvent or a recycled green solvent, providing the desired intermediates efficiently, while the by-product formed can be recycled.

How would you set this article in a wider context?

The use of traditional organic solvents, in particular, once spent, leads to organic waste which is to a large degree burned. These carbon-containing solvents, therefore, produce CO₂, a greenhouse gas, and hence, are contributing in a major way to climate change.

What is the motivation behind this work?

There is a need for all of modern organic chemistry to be redone, as it was developed over the past ca. 200 years based on organic solvents that predominantly derive from petroleum. The world needs methods, such as this one, which is representative of the possibilities for doing the same chemistry, but in an environmentally responsible manner.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

Perhaps the most exciting aspect is the fact that the thioester intermediates initially formed are precursors to more types of products than the esters and other thioesters reported in this paper. In other words, they are also amenable to amide/peptide bond formation, which is the number one type of bond needed in the pharmaceutical industry. Thus, this technology was applied to the synthesis of nirmatrelvir, the key ingredient in Paxlovid. Once the amide/peptide is formed, the by-product can be easily recycled, so the amount of waste created is very low. This approach also applies to reduction of the same thioester intermediates, which represents a solution to the acid/ester issue that has for decades been done using highly dangerous and flammable hydride reagents, such as LAH and DIBAL. This alternative technology for the same reductions can now be accomplished in very inexpensive, water-containing 95% EtOH. The challenge was to find the “right” intermediate that allows each of these types of reactions to take place. As usual, the answer was to look to Nature, which has had over 4 billion years to develop solutions, as was found and applied to these fundamental problems.

What is the next step? What work is planned?

Applications; sequences; and direct comparisons. Applications:  there is no shortage of bioactive targets that are currently made using traditional, waste-generating activating reagents in waste-generating organic solvents and hence, need to be “re-made” from the green perspective. Sequences, meaning that chemistry involving these new technologies can be telescoped, thereby leading to multi-step processes run in a single vessel. And comparisons, showing the chemistry community, by known examples that going “green” always wins; always.

Please describe your journey to becoming part of the Green Chemistry community

It started by chance back in 2006, when our campus Health & Safety Director informed me, after their weekly pick up and recording of our organic waste, that my group was not only the largest waste-generating on campus or the largest waste generating group in the city of Santa Barbara; but that we were the largest polluter in all of Santa Barbara County. From that moment on, since the vast majority of waste is organic solvents, we focused on developing chemistry in Nature’s chosen reaction medium:  water.

Why did you choose to publish in Green Chemistry?

The readership knows that all papers must pass a rigorous evaluation of “greenness”; that if a paper is published in this journal, the work represents truly environmentally sound chemistry. Hence, as the world begins to shift towards sustainability, papers in Green Chemistry will take on a special meaning:  they represent environmentally friendly processes that are in line with the future, encouraging an awareness that must be eventually considered in all that we as chemists do.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

The most important action that this journal has taken in my view these past 25 years is its claim to the field:  it was an incredibly timely to claim its title:  Green Chemistry. This alone tells the reader all that one needs to know! Other journals getting into the area realize this, and have been/are trying desperately to compete; to find a way to get a similar meaning across. And while certain markets might allow for this competition, the reality is that Green Chemistry highlights the chemistry of the future.

The main challenges over the next 25 years are not in terms of the chemistry that appears in this journal, or any other journal catering to this area. New technologies will be developed and added to a growing toolbox. The problem that has been and is likely to remain is:  people. The science is there, and it will continue to get better. But people can get in the way: egos, money, changing regulations, job security, etc. This is the problem that Green Chemistry, and all journals dedicated to this essential field, must solve. This can be done, over time, with creative thinking, some financial backing, and a lot of effort. The success stories need to be told to a broad audience, and positioned in a way that makes each personal, with which the people reading/listening identify and have influence. We may never have a better chance to do this than today, with sustainability being a buzzword, and especially, climate change on most minds. But will we?

The Lipshutz research group

The Lipshutz research group continues to develop new technologies in green chemistry, with the specific goal being to get organic solvents out of organic reactioons, as organic solvents are, by far, responsible for most of the organic waste created by the chemical enterprise, and derive mainly from finite petroleum reserves. To accomplish this goal, the concept of “designer” surfactants has been introduced within the area of aqueous micellar catalysis. The nanoparticles that form in water from these amphiphiles act as nanoreactors, enabling key transition metal-catalyzed cross-couplings, and many other reactions, to be carried out in water under mild conditions.

The group has also focused its attention on developing new catalysts for key Pd- and several other transition metal-catalyzed reactions that enable C-C, C-N, and C-H bond formation typically at the parts per million level of the metal. Most recently, these newly developed technologies in chemo catalysis are being merged with enzymatic processes, done in tandem in 1-pot, and all in water.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Critical review focusing on lignin, a biopolymer found in plants and trees (DOI: 10.1039/D4GC00745J). Chemical modifications of lignin are discussed and compared to each other in terms of sustainability aspects such as waste production and safety of the employed procedures. This literature review aims to increase awareness of the environmental implications that certain chemical procedures have, moreover wants to serve as a guide for researchers and industries towards more environmentally friendly practices.

Read our interview with the authors.

How would you set this article in a wider context?

There is the need to increase awareness regarding sustainability aspects and we, as scientists, are in a key position to drive sustainable innovations and environmental awareness further. Our article addresses not only the important renewability aspect of lignin, but also emphasizes practical insights as well as safer and less waste producing approaches. Beyond academia, the concepts and methods we discuss are relevant to industries looking for ways to reduce their environmental footprint, for example by utilizing lignin byproduct as a precious starting material for further applications.

What is the motivation behind this work?

The utilization of renewable resources has been a core principle of sustainable chemistry, since Anastas and Warner introduced the 12 Principles of Green Chemistry in 1998, which lay the foundation of sustainable development in chemistry. In this context, lignin remains an underutilized and often overlooked resource. Moreover, usually protocols focus only on the renewability aspect apported by lignin, often neglecting critical factors like toxicity, waste generation, and the reliance on additional petrochemical-based reactants. Our work aims to provide a systematic overview of the key protocols present in the literature based on the environmental factor (E-factor) for waste generation as well as toxicity aspects. We also categorized protocols based on the functional groups introduced to lignin, facilitating readers seeking targeted modifications.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

The most exciting aspect of this work is the opportunity to explore and expand the potential of lignin as a sustainable resource. We are particularly enthusiastic about continuing our research into innovative and more sustainable modification techniques for this biopolymer, which could open new possibilities for its application. However, one of the main challenges we faced was obtaining sufficient data for accurate E-factor calculations, as some previous studies did not report critical information such as reaction yields for lignin modifications. We thus also hope our work encourages researchers to consistently report comprehensive data and to also apply metrics for sustainability comparison.

What is the next step? What work is planned?

This review summarizes established procedures for lignin functionalization, along with essential principles for assessing the sustainability and safety of these processes. This assessment was important for us in identifying critical issues related to lignin modification and in designing safer and more sustainable modifications protocols. We would further be very happy if our review would be of value to other research teams in helping them to develop more sustainable uses of lignin within their respective fields of expertise. Currently, we are exploring alternative methods for lignin modification focusing of the use of lignin as macromonomer for various cross-linked polymeric materials.

Please describe your journey to becoming part of the Green Chemistry community

Our group has a strong research focus on Green Chemistry for about 20 years, in particular on the utilization of renewable materials in the most sustainable way possible. It was clear from the beginning that Green Chemistry is the way to contribute to some of the most important challenges of our society. Within the last years, seeing climate change advance and the dependence on fossil resources remain high, our dedication further strengthened – we are happy to be part of this growing community and that Green Chemistry has developed to a mainstream topic over the years. With this growth and all its positive aspects of new and exciting ideas and developments, however, we have to be careful of greenwashing also in academic research.

Why did you choose to publish in Green Chemistry?

We chose to publish in Green Chemistry because it is a highly renowned journal in the chemistry field, that aligns closely with our dedication to sustainable chemistry. Our manuscript discusses and compares different protocols for lignin modification based on their adherence to the principles of Green Chemistry, making this journal the ideal platform to reach a readership dedicated to similar goals. We are excited to contribute to this field and believe our work complements the journal’s mission to promote scientific advancements in sustainable chemistry.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

The journal Green Chemistry has always set high standards in this field by publishing innovative research with sustainable chemistry practices, it was and is a highly important part for the development of the research community. As the demand for greener solutions increases, it will be essential for the Green Chemistry community to continue developing innovative methodologies, ensuring that new processes are implemented by industry in order to contribute to a sustainable development. This is not an easy task, as fossil resources and environmentally unbenign approaches are often established and economically favorable, for instance because the cost of environmental burdens or greenhouse gas emissions are externalized to society. CO₂ pricing might be the necessary gamechanger here, hopefully allowing many of the advances reported by the Green Chemistry community to be put into practice. A further and ongoing requirement will be societal awareness, improved for instance by education and outreach activities.

Meet the authors

	Celeste Libretti received her B.Sc. degree in Chemistry and Technologies for the Environment and Materials, and subsequently her M.Sc. degree in Industrial Chemistry, both from University of Bologna. She is currently a Ph.D. student in the working group of Prof. Dr Michael A. R. Meier, at the Karlsruhe Institute of Technology (KIT). Her research interests include cellulose and lignin structural modifications, as well as green chemistry.
	Luis Santos Correa is a Ph.D. student working in the group of Prof. Dr Michael A. R. Meier at the Karlsruhe Institute of Technology (KIT). He received his B.Sc. and M.Sc. degree in chemistry from KIT. His master thesis focused on the oxidative cleavage of sunflower oil. He is currently working on the synthesis of polycarboxylic acids from renewable resources and their potential application in polymer chemistry.
	Michael A. R. Meier studied chemistry in Regensburg (Germany) and received his Ph.D. from the Eindhoven University of Technology (The Netherlands) in 2006. After further stays in Emden and Potsdam, he was appointed as full professor at the Karlsruhe institute of Technology (KIT) in 2010. He has received several awards and is associate editor of ACS Sustainable Chemistry & Engineering. His research interests include the sustainable use and derivatization of renewable resources for polymer chemistry as well as the design of novel highly defined macromolecular architectures.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on a strategy to prepare hydrogel drug slow-release carriers for efficient mosquito larvae extermination using green biodegradable materials. (DOI: 10.1039/D3GC03625A).

This strategy provides a new way to expand the application of liquid marbles in green chemistry. The highly stable, highly loaded, and biodegradable slow-release hydrogel carrier was prepared based on liquid marble utilizing green and cheap materials for loading pyrethrin to kill mosquito larvae. The liquid marble endowed the drug carrier with superior floating stability at the water surface to kill mosquito larvae hanging below the water surface for survival and the electrostatic interaction between alginate and gelatin of this carrier can effectively reduce the degradation rate of pyrethrin in water exhibiting a long drug release time.

Read our interview with the authors.

What is the motivation behind this work?

People living in humid environments, especially next to lakes and swamps and in rainforests, are often attacked by mosquitoes. So we wanted to prepare a green biodegradable drug slow-release carrier loaded with green anti-mosquito drug (pyrethrin) to kill mosquitoes without damaging the local environment.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

We find it most challenging to use the green route to impart good hydrophobicity and superior material stability to the drug carriers, and we are very excited about the long drug release time and superior floatation and storage stability of the drug carriers we have prepared.

What is the next step? What work is planned?

Our next steps will be to explore some research around liquid marbles in other directions of green chemistry. We will use the characteristics of liquid marbles to do some work in the fields of drug loading, adsorption and separation, and catalysis.

Please describe your journey to becoming part of the Green Chemistry community?

We wanted to reduce the number of mosquitoes in our living environment through green chemistry without damaging the environment, so we did work in this area. Green Chemistry, a top journal in the field of chemistry focusing on green chemistry and sustainability, was a perfect fit for our work, so we published our work in Green Chemistry.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

We consider that what the Green Chemistry journal has done best over the past 25 years is to provide a unique forum for the publication of innovative research in green chemistry as well as sustainable development. green chemistry is at the forefront of an evolving interdisciplinary field, so it is important to keep an eye out for innovative advances in green chemistry across disciplines.

Meet the authors   

	Qihui Zhang is a Professor of Pharmaceutical Chemistry at Chongqing University, who received his PhD degree from Shenyang Pharmaceutical University. As a senior visiting scholar, he finished his advanced study at the University of Chicago under the tutelage of Chair Professor Chun-Su Yuan. Professor Zhang is also the invited reviewer for more than ten top international journals. The main research interests of Professor Zhang include extraction, separation and structural modification of natural products based on molecular imprinting technology and nanotechnology.
	Liandi Zhou, born in 1978, Ph.D., graduated from China Medical University in 2008, Associate Professor, Director of Pathogenic Biology and Immunology Department, School of Basic Medical Sciences, Chongqing College of Traditional Chinese Medicine, Director of Chongqing Microbiology Society, and former expert of Chongqing Municipal Science and Technology Commission for reviewing medical projects. He has participated in one national-level project, two school-level projects of Chongqing Medical University, two planning textbooks of Science Press, and one school-level teaching reform project of Chongqing Medical University, and has published five papers on teaching reform. Her main research interests include the regulation of immune-related diseases by active ingredients of traditional Chinese medicine and their mechanisms, and she has published more than 20 SCI papers as a corresponding author.
	Dr. Saimeng Jin obtained his PhD degree in chemistry from the University of York (United Kingdom, with Prof. James Clark) in 2017 and his BSc degree from the Sichuan University (China, with Prof. Bi Shi) in 2010. He currently works as a Associate Professor at the School of Chemistry and Chemical Engineering, Chongqing University. He hosts the National Natural Science Foundation of China (No. 22208036). His research interests include dimethyl carbonate chemistry, conversion of biomass.
	James Clark is Professor of Chemistry at the University of York, and is Founding Director of the Green Chemistry Centre of Excellence and the Bio-renewables Development Centre. He is also Chair Professor at Fudan University in China and holds honorary doctorates at the Universities of Ghent, Leuphana and Umea. He is a Visiting Professor at Sichuan University and was the International Visitor at the University of cape Town. He has won prizes and awards from many organisations including the 2018 Royal Society of Chemistry Green Chemistry Prize and the 2021 European Sustainable Chemistry award. His research involves the application of green chemical technologies to waste or low value feedstocks notably biomass so as to create new green and sustainable supply chains for chemical and material products. Some of his discoveries in research include a new bio-based solvent Cyrene® to replace toxic amides (produced by Circa Group Ltd including in a new €50M manufacturing plant in France), unique bio-based carbonaceous materials (commercialised through his award-winning spin-out company Starbons® Ltd with applications in areas including medical devices) and new routes to waste plastics recycling (through his new spin-out company Addible.Ltd). James has also been very actively involved in green chemistry publishing, education and networking: he was founding editor of the world-leading Green Chemistry journal, heads the advisory board for the RSC Green Chemistry book series and he was founding director of the worlds’ longest running green chemistry MSc program as well as the Green Chemistry network and the Global Green Chemistry Centres network. (“G2C2”).

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Critical Review that summarizes the primary types of carbohydrate chemical transformation and commonly used solvent systems, providing an overview of solvent effects in these reactions and an insight into solvent effects from a microscopic perspective (DOI: 10.1039/D3GC04901A) The review also provides relevant insights into the current status and challenges of solvent engineering, contributing to the solvent construction of carbohydrate reaction systems.

Read our interview with Haipeng Yu, the corresponding author here:

How would you set this article in a wider context?

The development of biomass resources is progressively moving towards refinement for higher-value benefits. Carbohydrates are an important component of biomass resources, and the chemicals obtained from their chemical derivatization are key intermediates in the production of biofuels, bioplastics, pharmaceuticals and fine chemicals, which makes carbohydrate resources a favourable alternative to traditional fossil energy sources. This article provides relevant insights into how solvent effects modulate carbohydrate reactions and also offers key information to optimize the reactions and improve their sustainability and environmental friendliness. The modulation of chemical pathways by solvents is a pervasive application. This article not only advances the understanding of biomass-derived chemical production, but also contributes to broader fields such as organic synthesis, materials science, industrial process design and green chemistry. It is hoped that this article will resonate across disciplines and provide a reference for more sustainable, efficient and targeted chemical processes.

What is the motivation behind this work?

We hope that this work will inspire future rationalized solvent design for specific chemical reactions. By understanding the mechanisms by which solvents regulate carbohydrate conversion pathways, researchers can develop novel and practical solvent systems that will improve the reaction efficiency and sustainability of a range of chemical processes.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

The most interesting and challenging part of this work is the exploration and demonstration of the interaction between the solvent and other substances in the reaction system. The influence of solvent regulation on experimental results can be jointly supported through experimental control and microscopic simulation.

What is the next step? What work is planned?

In the next step, we plan to utilize solvent effects to develop related fine chemicals based on the sugar platform.

Please describe your journey to becoming part of the Green Chemistry community.

My journey began in my graduate studies when I recognized the environmental impact of traditional chemical processes, and I was inspired by sustainable chemistry to delve deeper into biomass conversion. I have been working on projects with my teachers and fellow students on green catalysts, synthetic routes, and bio-based materials. In the process I have come to understand the Green Chemistry community and become a part of it. In the future, I will take green chemistry as my purpose and continue to focus on the development of sustainable biomass conversion and utilization.

Why did you choose to publish in Green Chemistry?

I chose to publish in Green Chemistry because it aligns with the commitment to advancing sustainable and environmentally friendly chemical processes. The journal is a leading platform for cutting-edge research that promotes the principles of green chemistry. By publishing in Green Chemistry, I have the opportunity to contribute to a global community of scientists who are focused on developing innovative, sustainable solutions that address environmental challenges.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

Over the past 25 years, Green Chemistry has played a pivotal role in advancing sustainable science by providing a respected platform for researchers to share groundbreaking work on environmentally friendly chemical processes. The journal has successfully promoted the 12 Principles of Green Chemistry, helping shift industry and academic focus toward designing safer chemicals, using renewable resources, and minimizing waste. It has also facilitated collaboration between chemists, engineers, and policy-makers, driving practical applications of green technologies in industries like pharmaceuticals, energy, and materials science.

However, as we look ahead to the next 25 years, scaling sustainable technologies for widespread industrial adoption remains a major hurdle, as many green alternatives still struggle to compete economically with conventional processes. The journal may need to focus more on scaling up the practicality and economics of green chemistry processes. Additionally, as global environmental policies and regulations evolve, the journal may need to adjust its focus and content to remain relevant and impactful, including a greater emphasis on topics such as chemical recycling, renewable resource, and carbon footprint reduction.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Critical Review on the application of Deep Eutectic Solvents (DESs) in the materials preparation process, starting from their unique and significant properties, combined with specific examples to propose how to design solvent systems according to various demands and purposes (DOI: 10.1039/D4GC00136B). The combination of green chemistry principles with innovative material design is expected to reshape industry technologies in a sustainable, efficient, and cutting-edge manner.

Read our interview with the corresponding authors

How would you set this article in a wider context?

This article not only provides a comprehensive summary of fundamental research but is also supported by practical case studies, offering convenience for chemists and material scientists in their research. Additionally, the economic feasibility and environmental impact have been evaluated, which may serve as a reference for policymakers.

What is the motivation behind this work?

The study of the properties of DESs has become quite mature, and therefore, their effective use has become a focal point. The heterogeneity of DESs is a characteristic of these solvents, but what is its relationship with morphology control? Why can DESs function not only as solvents but also as templates and reducing agents? These deeper questions have been explored, but systematic discussions and comparisons are lacking. We have bridged two aspects of this field: starting from the excellent solubility of DESs to the preparation of various functional materials.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

Pairwise summarization of work presents challenges, for example, inserting-leaching, etching-coating, doping-compositing, bottom-up and top-down approaches. Additionally, summarizing the electrodeposition of pure metals and common alloys is also a complex task.

What is the next step? What work is planned?

Moving forward, our work will continue to focus on green chemistry research in the following areas:
a. Forestry Resource Chemistry: pretreatment and high-value conversion of biomass and platform compounds
b. Resource and Environmental Chemistry: separation and purification of greenhouse gases, VOCs, waste plastics, minerals, and electronic waste

Why did you choose to publish in Green Chemistry?

All along, Green Chemistry is one of the most influential journals in this field. Green synthesis, green manufacturing and green energy are all inseparable from the basic concept of green chemistry. We believe that this work will demonstrate its greatest impact here.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

From the proposal of the 12 principles of green chemistry to the establishment of the journal Green Chemistry, scientists have gradually built a solid foundation for their research efforts. We believe that over the past 25 years, Green Chemistry as a publication has consistently promoted the concept of a sustainable society and the continuous development of humanity. In the next 25 years, the key will be how to attract high-quality research for publication, especially given the intense competition already evident within the publishing industry. More importantly, it is crucial to gain insights into the chemical elements involved in green development, thereby guiding progress in related fields.

Meet the corresponding authors

Prof. Tiancheng Mu received his Ph.D. in physical chemistry from the Institute of Chemistry, the Chinese Academy of Sciences, in 2004. He worked in the Department of Industrial Chemistry, Oldenburg University, as a postdoc from 2005 to 2007. He is currently a full professor in the Department of Chemistry, Renmin University of China. He has authored over 200 peer-reviewed scientific publications and six book chapters. He currently serves as an Associate Editor for RSC Advances, and as an Advisory Board Member for CLEAN – Soil, Air, Water. He is vice-director of the Ionic Liquids Committee of the Chemical Industry and Engineering Society of China.

Prof. Zhimin Xue received her Ph.D. degree from Renmin University of China in 2014. From 2018 to 2019, she was a visiting associate professor at the University of Tennessee, Knoxville. She is currently a professor at Beijing Forestry University. Her research interests cover the treatment and conversion of biomass, design, and applications of green solvents. Furthermore, she was awarded the Prize of Liangxi Forestry Science and Technology Award and the Science and Technology Award of the China Association for Instrumental Analysis. She was selected for the National High-level Talent Special Support Plan in 2021.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on quantifying  the level of correlation and linkages between five mass- and energy-based metrics and 16 LCA indicator scores by leveraging data for over 700 chemical manufacturing processes (DOI: 10.1039/D4GC00394B) Synthetic chemicals are essential to everyday life, supporting everything from food security and health care to electronics and clothing. Scientists and engineers are constantly searching for greener production routes, but designing them requires methods to quantify their environmental impact. This article evaluates different metrics of varying complexity, identifying their pros and cons.

Read our interview with Javier Pérez-Ramírez and Gonzalo Guillén-Gosálbez

How would you set this article in a wider context?

Global chemical demand is projected to grow by 40% this decade, while the chemical industry faces mounting pressure to reduce its substantial environmental footprint. We highlight the critical role of metrics in assessing environmental impacts and emphasise the importance of a holistic approach to guide prioritisation and more informed decision-making.

What is the motivation behind this work?

Overall, our goal is to promote the broad adoption of quantitative metrics in research. The global aspiration of the community to make the world a better place through chemistry often relies on narrow or simplified indicators, leading to unclear environmental benefits. We addressed this by using more comprehensive and standardised approaches across a wide range of key chemical processes to understand the differences in the information they provide.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

We’re particularly excited about how comprehensive sustainability metrics like life cycle assessments (LCA) can rank chemical processes based on diverse environmental impacts, going beyond the CO₂ footprint. Our results indicate that different methods present distinct advantages and trade-offs across various environmental criteria. Current challenges include the limited availability and uncertainty of openly accessible data, as well as the need to bring the experimental and systems engineering communities closer in the coming years.

What is the next step? What work is planned?

We conclude from our results that increasing the use of comprehensive LCA in early research stages is key. To address this, we aim to make these environmental analyses more accessible through user-friendly tools. Additionally, we will focus on data standardisation and robust methods for managing data uncertainty, as well as proposing effective schemes for ranking chemicals based on distinct impacts, which remains challenging.

Please describe your journey to becoming part of the Green Chemistry community

We view our journey into the Green Chemistry community as a natural progression of our commitment to making a positive societal impact. Chemistry will play a pivotal role in implementing the sustainable development goals and combating climate change, and we believe that embracing the guiding principles of Green Chemistry is essential for this mission within an interdisciplinary approach.

Why did you choose to publish in Green Chemistry?

We chose Green Chemistry for its unique focus on alternative green technologies and sustained leadership in the field. The themed collection ‘Measuring Green Chemistry: Methods, Models, and Metrics‘ aligns with our focus on quantifying environmental impacts, making it the ideal platform for our study.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

Green Chemistry has been instrumental in uniting a diverse community under a shared philosophy grounded in the Green Chemistry principles and has successfully adapted to the evolving landscape of sustainable chemistry. As mentioned above, one of the major challenges will be achieving the application of standardised metrics in both academic and industrial arenas, for which different stakeholders must collaborate.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together as very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on the application of a highly recyclable heterogeneous catalyst to the multi-decagram synthesis of enantiomerically enriched molecules in continuous-flow using a 2 mL reactor. The combination of this catalyst with a new reactor design increased the productivity from milligrams to up to 20 g scale in a few hours while reducing the overall environmental impact of the reaction (DOI: 10.1039/D4GC00019F)

Organocatalysis has become one of the pillars of asymmetric catalysis along with metal and enzyme-catalyzed reactions. Its potential was recognized in 2019 by the IUPAC, as a part of the top 10 emerging technologies in chemistry, and by the Nobel Prize awarded to Benjamin List and David MacMillan in 2021.However, these reactions are often too inefficient due to the high catalyst cost and scalability issues, leading to limited applicability in the industry. In this context, developing heterogeneous catalysts can simplify the recycling process, making catalytic processes more efficient and contributing to minimizing the overall cost and environmental impact of the reaction.

Read our interview with Aitor Maestro and C. Oliver Kappe

What is the motivation behind this work?

Although the use of heterogeneous catalysts and continuous flow technology in asymmetric catalysis is not new, the productivity of known processes is often rather limited. Developing new and reliable enantioselective processes for reproducing batch reactions on a large scale requires a combination of chemical and technical solutions. In this article, we wanted to illustrate the potential of combining these techniques to achieve higher productivity and set up a precedent for future developments in the field.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

One of the most exciting results of this project was the high robustness of the heterogeneous catalyst. While similar homogeneous reactions often require 2-10 mol% of the catalyst, we managed to decrease it up to 0.1%. Moreover, the analysis of the catalyst after the reaction did not show any visible physical or chemical degradation, indicating it could be used for much longer.

One of the biggest challenges is the development of new heterogeneous catalysts that efficiently mimic the behaviour of their homogeneous counterparts. While solid supports facilitate the recycling process, they can also affect the reactivity.

What is the next step? What work is planned?

We are willing to further explore the potential of highly active heterogeneous chiral catalysts for other applications in the future. We want to apply them to the synthesis of key chiral building blocks and active pharmaceutical ingredients.

Please describe your journey to becoming part of the Green Chemistry community

Integrating technical solutions with intricate catalytic reactions helps reduce the overall waste, create more sustainable chemical processes, and enhance reaction efficiency. Therefore, focusing on the intersection of catalysis and technology aligns perfectly with the principles of green chemistry.

Why did you choose to publish in Green Chemistry?

This is one of the leading journals in the field of green chemistry research. We thought our work involving catalyst recyclability studies and waste reduction of the reported enantioselective reaction was a good fit for the scope of the journal.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

One of the biggest challenges for the journal is being focused on a constantly changing field. Many aspects of green chemistry are often directed by global trends or new legal regulations. Some current challenges that will probably get more attention in the coming years are obtaining raw chemicals from renewable sources such as CO₂ or the development of economically viable catalytic processes.

Meet the corresponding authors

Aitor Maestro obtained his PhD (2019) from the University of the Basque Country, working on asymmetric organocatalysis. After two postdoctoral stays (University of Groningen, and University of St. Andrews), in 2022, he obtained a Postdoctoral Fellowship from the Basque Government, allowing him to spend two years at the University of Graz working on asymmetric catalysis in continuous flow before moving back to the University of the Basque Country, where he is currently working on independent projects related to the development and applications of recyclable chiral catalysts.

Oliver Kappe received his diploma (1989) and his doctoral (1992) degrees in organic chemistry from the University of Graz and after two postdoctoral stays (University of Queensland and Emory University) returned to Graz in 1996 to start his indepenent acacdemic career and was appointed Full Professor in 2011. For the past decade the focus of his research has been directed towards flow chemistry/microreaction technology, encompassing a wide variety of synthetic transformations and experimental techniques.

Over the past 25 years, Green Chemistry has provided a unique forum for the publication of innovative research on the development of alternative sustainable technologies, efficient utilisation of resources and the concomitant minimisation of waste. We are delighted to bring together a very special issue containing articles by members of the green chemistry community as well as past and present Green Chemistry Board members, to mark and celebrate our first 25 years.

Among the contributions to this themed collection is a Paper on the promotive effect of Au and Sn incorporation into supported Pd nanoparticles for the direct synthesis of H₂O₂ from molecular H₂ and O₂  (DOI: 10.1039/D3GC03706A).

The direct synthesis of H₂O₂ from the elements represents an atom-efficient alternative to the current indirect industrial process, allowing for localised production of a major commodity chemical used in sectors as varied as chemical synthesis, bleaching and disinfection. However, despite over 100 years of research, few examples of highly selective catalysts (i.e. those that do not degrade H₂O₂ to H₂O), exist. Catalysts based on PdAu and PdSn active sites are an exception to this generality and this work compares and contrasts the efficacy of these two systems towards H₂O₂ production and demonstrates the excellent performance metrics which can be offered by these two distinct classes of materials.

Read our interview with Dr Richard J. Lewis, one of the authors, here.

How would you set this article in a wider context?

AuPd catalysts have been well studied in recent decades for a range of chemical transformations, including H₂O₂ synthesis. However, the replacement of Au with Sn, and the resulting improvement in catalytic efficiency that results, is a relatively new discovery, with earlier works in this area focussed on (i) the use of complex catalyst synthesis protocols to form Sn overlayers that encapsulate highly active yet unselective Pd species or (ii) the study of idealised, model PdSn catalysts in order to gain a fundamental understanding of the structure-reactivity relationships that exist in such systems.

Importantly the materials studied within this work are produced via a readily scalable synthesis protocol and compete with state-of-the-art materials reported within the academic literature, including those previously reported by our laboratory. Crucially they can achieve the high selectivity necessary for the direct route to H₂O₂ synthesis to compete with the current industrial approach to production.

What is the motivation behind this work?

Despite calls for uniformity in testing regimes, it is typical for stark differences in catalyst evaluation protocols and reaction conditions to exist between research groups. This is somewhat understandable given that researchers wish to evaluate catalytic performance under conditions idealised for their particular system, as well as allowing  for benchmarking against earlier works from their own laboratory. However, this often leads to confusion as to the current state-of-the-art, with comparison of catalysts, especially those from different laboratories, under standardised conditions rarely performed. In this work, we set out to address this concern, comparing and contrasting the performance of a series of catalysts based on the well-established AuPd formulation, against the emerging class materials centred around PdSn.

What aspects of this work are you most excited about at the moment and what do you find most challenging about it?

The performance of our 0.25%Pd–2.25%Sn/TiO₂ catalyst is particularly exciting, offering near-total selectivity towards H₂O₂ and product yields superior to the optimised AuPd formulation. Indeed, the performance of this catalyst can be considered among the state-of-the-art.  The mechanism by which this improved reactivity is achieved is also intriguing, with the addition of high quantities of Sn promoting Pd dispersion and the formation of highly active and selective, single atoms of Pd surrounded by Sn/SnO_x domains, rather than through the formation of PdSn alloys as may have been expected based on earlier works.

What is the next step? What work is planned?

While these systems are highly promising it is important to note that they represent only the first generation of materials developed in this project. As such our focus has now shifted towards the redesign and further optimisation of these catalyst formulations to ensure the key performance metrics (high reactivity and near-total selectivity towards H₂O₂) are maintained over industrially relevant lifetimes. We are also actively pursuing the translation of these research-grade catalysts into technical-grade materials to allow for further evaluation under realistic operating conditions, as well as use in alternative chemical transformations centred around the utilisation of in-situ synthesised H₂O₂.  We are also seeking a greater understanding of the dynamic nature of these systems during catalysis, through the use of operando and in-situ characterisation techniques. This is particularly exciting and allows us the opportunity to collaborate with colleagues from fields adjacent to catalysis, including spectroscopists and microscopists.

Please describe your journey to becoming part of the Green Chemistry community

Engineering a more sustainable world aligns perfectly with the aims of the Green Chemistry and Catalysis communities, as such it is easy to consider the members of these two fields as part of the same family, rather than belonging to two distinct communities whose goals are sometimes shared.  Therefore there has not been a journey towards a Green Chemistry community, rather there is a shared journey with friends and colleagues of one community.

Why did you choose to publish in Green Chemistry?

Green Chemistry is, without doubt, one of the flagship journals in the field of sustainability, built on the foundations laid out by Paul Anastas and Nicolas Eghbali and nurtured by past and present members of the journal Editorial Board. One of the major themes of  Green Chemistry is to find solutions to many of the grand challenges facing the chemical industries through the design, synthesis and evaluation of novel materials and alternative processes. We consider that our manuscript aligned very well with these ambitions and given the broad readership of the journal, we could think of no better home than Green Chemistry.

What do you think the Green Chemistry journal has done well in the past 25 years, and what do you think are the main challenges our community will face in the next 25 years?

For the past 25 years, Green Chemistry has been at the forefront of advances in sustainability and environmental protection, continually promoting the development of new technologies that improve efficiency and minimise the impact of the chemical sector, both to humans and the wider ecosystem. A major challenge facing the chemical sector has and will continue to be the transition towards manufacturing processes that better utilise raw materials and minimise the production of waste by-products. This challenge will only grow with the transition toward alternative, non-fossil-derived feedstocks supplied from a wide variety of sources.  The drive towards Net Zero poses both challenges and opportunities for the field, with the emergence of new feedstocks including sequestered CO₂, NH₃,  biomass and carbon-free H₂ requiring the development of new processes and modifications to existing technology. The associated shift towards electrification will also result in changes in supply/demand dynamics of critical elements that will undoubtedly result in increased utilisation of many earth-abundant metals (e.g. for use in energy storage), while the shift away from fossil fuel-based transit will have unpredictable effects on the supply of many of the precious metals that are utilised in petroleum refining and automotive exhaust treatment and have been the backbone of the chemical synthesis sector.