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 where a simple and recyclable homogeneous catalytic system for the hydrogenation of carbon monoxide to methanol was established (DOI: 10.1039/D4GC01050G).

Read our interview with Andreas J. Vorholt, one of the corresponding authors.

Could you briefly explain the focus of your article to the non-specialist? The homogeneously catalyzed synthesis of methanol overs several advantages over its heterogeneous counterpart such as milder conditions, higher selectivity and one-through conversion. However, catalyst recycling remains an inherited challenge for the industrial application of such processes. This work gives the first demonstration of the recycling of a homogeneous catalyst system based on the earth’s abundant metals manganese with high productivity and excellent selectivity.

How would you set this article in a wider context?

Methanol is considered a central pivot between energy and chemical industry for sustainable transformation. While the established heterogeneous methanol production process benefits from economies of scale, homogeneous catalytic processes are better suited for small to mid-size decentralized production coupled with fluctuating renewable energy supply. This article marks a key step towards such processes by demonstrating the successful, yet inherently challenging, recycling of the employed Mn-based catalyst.

What is the motivation behind this work?

In the past couple of years many systems were developed in the field of homogeneous methanol synthesis either from CO or CO2. However, all those examples were far from industrial applicability as they did not address the challenge of catalyst recycling and simple product separation, which is essential to make such a process economically viable. Therefore, based on our earlier work in this field, we aimed to establish a simplified system that can address these challenges by simple unit operations.

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

For a transformation that was seen as highly challenging in the past, the simplicity of the developed system, comprising only of the catalyst, the cheap base NaOMe and a long-chain alcohol, is fascinating.

What is the next step? What work is planned?

As we have shown that the catalyst can be recycled batchwise, we are now taking it one step further and employing this system in a continuous operation incl. constant product separation and catalyst recycling. This will get us significantly closer to industrial usability.

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

I started my way in the GC community already in my PhD, when I worked on the conversion of oleochemicals to monomers. Later I wrote a master thesis in my economics studies on the future of renewables under the GC conditions. I was finally caught by the idea after the Gordon Green Chemistry Conference in Hongkong.

Why did you choose to publish in Green Chemistry?

Green Chemistry is at the forefront of the sustainable development of the Chemistry community as a whole. Every article published in this journal aims contribute a small piece to overcoming the great challenges the chemical industry and our entire society are facing today. We are convinced that our manuscript very well aligned with the goals of the journal and it gives us the perfect platform to present to and discuss with an audience that holds the same values and goals to drive the sustainable transformation of 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 advanced sustainability in the chemical research from a nice side-bonus to the number one goal of modern-day chemists and engineers. Starting from the 12 Principles of Green Chemistry this journal as a platform has fostered the awareness, importance and acceptance of sustainable chemistry. For the next 25 years ahead one major challenge will be to bring the tons of brilliant ideas that are published in great journals like Green Chemistry out of the lab into practice. Only if we will achieve this fast enough, we will be able to solve the enormous challenges ahead of us.

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 paper that  offers insights into an assessment approach for evaluating the environmental sustainability of either single chemical transformations or entire processes (DOI: 10.1039/D4GC00302K).  It adopts a multi-dimensional framework, presented in a practical and systematic manner. This approach relies on a clear starting point for all assessments, making use of available data, simulating missing data, to allow for fair comparisons. This comes to improve on the too often used mono-dimensional analyses that have by now proven a potential source for incorrect conclusions and decisions.

Read our interview with the authors, Michael U. Luescher and  Fabrice Gallou:

How would you set this article in a wider context? 

While we do understand that our methodology is far from being 100% accurate, it has proven its reliability against more complex LCA-methodologies in identifying environmental hotspots. This more pragmatic approach enables us to look at, and impact, entire portfolios of industrial companies and guide research interest enabling real returns in the longer term. Besides, we believe that this article should be seen as steppingstone and a first step towards the next generation of metrics, moving away from the one-dimensional approaches, that have served us well in the past and brought us up to this point, and gearing towards LCA-type of analysis.

What is the motivation behind this work? 

Moving away from opinions and one-dimensional assessments, we looked to establish a method to take data driven, educated, sound decisions on a large scale. The timing of such assessments becomes more critical as many transformations can now be done using multiple technologies, which can require extensive investment, and whose overall footprint is not necessarily well understood. Hence the need to establish more tools to support our decision-making process.

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

We are very excited at how our methodology has been performing within our organization, the impact it had on our decision taking, and hope that we can share these learnings with the wider community, as we do not consider this a competitive advantage. It is all the more exciting as it has proven to bring real value in terms of multiple aspects of sustainability and can lead to good decisions with tremendous impact on the planet!

What is the next step? What work is planned?

We plan to further streamline the methodology, implementing it company wide, and to illustrate in the future how this approach has helped us select the better options which led to significant impact on the footprint of the syntheses and processes at stake.

Why did you choose to publish in Green Chemistry? 

Green Chemistry has had a long history of gathering the community and disclosing high quality content. It has in our mind further increase its leadership position and authoritative position in this field in the recent years and was thus the obvious choice for us.

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?

In a first phase, the journal has had tremendous impact raising awareness and educating. More recently, it has in our mind further stepped up being not just a source of inspiration and education, but also really pushing the boundaries of science with impact on sustainability.

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 reporting a mechanochemical and aging-based method to alkylate Chitosan via reductive amination  (DOI: 10.1039/D4GC00127C).

Read our interview with Audrey Moores, one of the corresponding authors.

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

Chitosan is an interesting material that can be extracted from crustacean waste and has antibacterial and biocompatibility properties. It has however limited solubility so it is very hard to modify its properties to meet our needs. Our group developed a way to functionalize it, and introduce new properties by reacting it in the solid-state giving easily access to, for instance, a more soluble version of chitosan.

How would you set this article in a wider context?

Nature is providing us with wonderful materials packed with amazing properties such as wood or crustaceans exo skeleton. Taking these materials and transforming them with simple and accessible chemistries is a great way for us to replace petrochemicals around us, but it is difficult to achieve because these materials are typically not soluble in most solvents. With this work not only do we demonstrate that working in the solid-state resolve this conundrum, but also we are able to achieve a higher degree of functionalization than similar chemistries in the liquid state.

What is the motivation behind this work?

Our group works in Quebec, which is one of the 13 provinces and territories of Canada. Quebec has an important fishery industry generating every year an estimated 40,000 tons of crustacean waste, currently unvalorised. We are developing a program to demonstrate that mechanochemistry and solid-state reactivity can provide a unique avenue for transforming this underutilized stream into functional materials useful for our societies.

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

This article is Clearly showcasing how mechanochemistry and solid-state reactivities could be a productive way to develop new products made from chitin, cellulose and chitosan.

What is the next step? What work is planned?

Our work is now geared towards new functionalization of this material so that we could expand our toolbox even further.

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

Green Chemistry started for me during my post doc, which I did under the mentorship of Professor Robert Crabtree at Yale University close to 20 years ago. Back then, Bob sent me to the Green Chemistry summer school of the ACS in Washington. At that event, I met many people including Paul Anastas, Julie Zimmerman and Phil Jessop, all legendary names in the field, who have motivated me to become part of the community. When I started my group at McGill, as a Canada research chair in Green Chemistry, it was thus natural for me to teach this topic, do my research according to its principles, and an encourage all my trainees to become active members in the community.

Why did you choose to publish in Green Chemistry?

Green Chemistry remains a flagship for our community, as the first journal in the field. I have published many articles in this journal and always appreciate the quality of the work from the team and the wide readership it provides.

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?

Looking back, it is evident to me that Green Chemistry has been a key player in making this topic front and centre in the field of chemistry at large. Honestly this is something that was not evident 25 years ago, and it is thus a huge achievement in my opinion. I think our community should look at the 25 coming years to make sure it becomes central as a science. Working in the field of sustainability, I feel there is still room for people to realize the immense role that chemistry and especially green chemistry can play in developing it further.

Meet the corresponding author

Audrey Moores is a professor of chemistry and associate director of the Facility for Electron Microscopy Research at McGill University. She completed her PhD at the Ecole Polytechnique, France and a post-doctoral fellowship at Yale University. She serves as an executive editor for ACS Sustainable Chemistry & Engineering. She became a member (2020) and president (2024-26) of the College of New Scholars, Artists and Scientists of the Royal Society of Canada. She received the Canadian Chemistry and Chemical Engineering Award for Green Chemistry (2021). With her group, she focuses on sustainable solutions for nanoparticles and biopolymer synthesis as well as catalyzed reactions, with an interest in waste biomass valorization, earth abundant starting materials and high atom economy and has been travelling globally to teach green and sustainable chemistry

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 production of low-cost high-quality carbon fiber using lignin alone without chemical treatment or additives (DOI: 10.1039/D3GC04288J).

Read our interview with Xianglan Bai, the corresponding author.

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

Low-cost green carbon fiber is of great interest due to its ability to improve material performance and decarbonize industries. For example, broader applications of low-cost carbon fiber in the automobile industry can improve fuel efficiency and reduce carbon emissions from the transportation sector. The US Department of Energy (DOE) stated in the early 2000s that carbon fiber with a tensile strength of 1.72 GPa and tensile modulus of 172 GPa at costs below $5-7/lb can be widely used in the automobile industries. Although lignin has been considered the most promising low-cost green precursor of carbon fiber, the major bottleneck and barrier in developing commercially relevant lignin-based carbon fibers is their poor mechanical properties far below the commercial petroleum-based carbon fibers. Previous approaches of chemically modifying lignin or processing lignin and co-precursors were ineffective in meeting the cost and property requirements of carbon fiber. We recently discovered a surprisingly simple and low-cost method to improve the tensile properties of lignin-based carbon fiber.  By integrating thermal heating and tension stretching during the carbon fiber processing, we successfully manipulated the intrinsic lignin chemistry and controlled material transformation. Our melt-spun carbon fiber made of unmodified raw lignin achieved unprecedented mechanical properties compared to previous lignin-based carbon fiber (tensile strength of 2.45 GPa and tensile modulus of 236 GPa). Its production cost was only $4.17/lb, suggesting its promising economic potential.

How would you set this article in a wider context?

In addition to traditional pulping industries, lignin is increasingly available as a low-cost byproduct from emerging biorefineries. Developing lignin-based high-value products with market-comparable scale holds the key to the economic sustainability of biorefineries. Lignin-based green carbon fiber can be attractive due to its enormous potential markets, such as the automobile and construction industries. However, previous approaches for producing lignin-based carbon fiber have been mostly unsuccessful due to the poor properties of the resultant carbon fibers. Thanks to the thermo-mechanochemistry of lignin discovered in our recent work, 100% lignin-based carbon fibers meeting the automobile-grade properties and cost requirements were achieved by simply controlling heat and tension applied during carbon fiber processing. The discovery of the novel chemistry of lignin and our proof-of-concept results will alter perceptions of lignin-based carbon fibers as the commercially viable low-cost green carbon fibers, therefore advancing lignin valorization in biorefineries.

What is the motivation behind this work?

Polyacrylonitrile, the standard carbon fiber precursor, has one dimensional repeated polymer structure. During its stabilization and carbonization process, the well-defined structure of polyacrylonitrile transforms into a highly oriented turbostratic graphene structure that offers exceptionally high mechanical properties. In comparison, lignin is an amorphous polymer with three-dimensional crosslinked network. During the conventional stabilization and carbonization process, the non-oriented lignin structure turns into an amorphous carbon structure with pores, which leads to poor mechanical properties. Because the intrinsic lignin structure lacking in molecular orientation is responsible for the poor mechanical properties of lignin-based carbon fiber, previous approaches mainly focused on chemically modifying lignin or blending lignin with other polymers or additives with well-defined linear structures. However, such efforts for modifying precursors were insufficient to overcome the tensile property issues of the carbon fiber.

Lignin undergoes extensive chemical transformation and microstructural changes during the thermal treatments required for producing carbon fiber. Thus, it may be possible to alter the chemical reactions of lignin and microstructural evolution through controlling the fiber processing conditions. However, this potential opportunity for modifying lignin has been largely overlooked. In previous studies, lignin-based precursors were oxidized and carbonized using empirical methods or the method initially developed for petroleum-based precursors. To address the knowledge gap, we carefully tracked the chemical structure and corresponding microstructural formation through various stages of fiber fabrication under different thermal and tension conditions. As a result, we found that combining proper thermal treatment and strong tension stretching of the fiber can manipulate chemical reactions and control the microstructure evolution, transforming lignin into oriented and graphene carbons at a surprisingly low temperature of 700 ℃. Based on our patent-pending fiber processing method tailored for lignin, high-quality carbon fiber can be obtained without needing costly co-precursors or chemical treatment.

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

The discovery of lignin’s thermo-mechanochemistry in our work will provide many exciting opportunities for converting lignin into interesting and higher-value products. Thermo-mechanochemistry is a new terminology our group invented for lignin, which was previously unknown. Since lignin structure depends on parent biomass origin and lignin extraction methods, more research is required to fully understand this new chemistry of lignin. Combining advanced analytical techniques and computational studies will help understand a novel material chemistry.

What is the next step? What work is planned?

We plan to expand our current research to investigate broader types of lignin. We will improve our understanding of lignin’s thermo-mechanochemistry by developing the structure-process-property relationships for different lignin and precursors. We will also continue to improve our methods to increase the mechanical properties of the carbon fiber and reduce production costs. We hope to collaborate with industries to demonstrate our carbon fiber processing method in scale and utilize lignin produced from different industrial processes.

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

I began my academic career as an assistant professor at Iowa State University in 2013. Since then, the overarching goal of my research group has been developing environmentally friendly and transformative technologies to valorize low-cost, abundant resources. Over the years, our group has developed broader expertise in thermochemical conversion, electrified conversion, and material synthesis to convert biomass, waste plastics, and greenhouse gases into fuels, chemicals, and carbon materials. Studying various technologies and feedstocks allowed us to gain expertise in developing integrated processes and multidisciplinary approaches for solving challenging problems in sustainability. In this work, we combined our knowledge of lignin chemistry and material science to investigate lignin-based carbon fiber, which led to the discovery of a novel material chemistry and a new lignin-tailored process for carbon fiber production.

Why did you choose to publish in Green Chemistry?

Green Chemistry is known for publishing high-quality frontier research on various sustainability topics. In this context, Green Chemistry has always been among the top choices to publish our research. Our group has a long history of publishing 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?

Green Chemistry journal has been widely recognized as one of the top journals in sustainability research. The journal has published many exciting and groundbreaking research. As environmental and energy issues remain grand challenges for our society, there is no doubt that Green Chemistry will continue to serve as an important platform for communicating scientific discoveries in the broader realms of sustainability. In terms of future challenges, improving the transformative aspect of the research findings to demonstrate technologies in scale and developing system approaches is strongly desired for the novel research to make a real-world impact.

Meet the corresponding author

Xianglan Bai is currently a Professor of Mechanical Engineering at Iowa State University. She is also a courtesy professor of Chemical and Biological Engineering at the same institution. She is the Editorial Board Member of Fuel Processing Technology and Carbon Neutrality. The focus of her research group is the valorization of biomass and waste plastics into fuels, chemicals, and carbon-based materials via developing novel thermochemical conversion, electrified conversion (non-thermal plasma and joule heating), and material synthesis.