Albert Matlack, one of the founding educators of green chemistry and author of the book ‘Introduction to Green Chemistry’, selects his favourite papers in Green Chemistry this month…
Mechanical depolymerisation of acidulated cellulose: understanding the solubility of high molecular weight oligomers, Abhijit Shrotri, Lynette Kay Lambert, Akshat Tanksale and Jorge Beltramini, Green Chem., 2013, 15, 2761–2768, DOI: 10.1039/c3gc40945g
In this work, cellulose was milled with sulfuric acid to produce oligomers which were hydrogenated over a Ni/Pt/aluminium oxide catalyst 200 °C for an hour to produce 90% of sorbitol and mannitol. This yield is better than the efforts of others to do the job. Sorbitol can be converted to isosorbide, then to high melting point biopolymers. Further work is needed to get more than the 34.6% of the starting cellulose to dissolve.
Continuous flow nanocatalysis: reaction pathways in the conversion of levulinic acid to valuable chemicals, Jose M. Bermudez, J. Angel Menéndez, Antonio A. Romero, Elena Serrano, Javier Garcia-Martinez and Rafael Luque, Green Chem., 2013, 15, 2786–2792, DOI: 10.1039/c3gc41022f
This work shows the advantages of a continuous flow system to produce biomass platform chemicals. The authors use a ThalesNano H-Cube of levulinic acid to produce 60% methyltetrohydrofuran and 40% 1,4-pentanediol in one minute at 150 °C, which shows the value of the system over a batch method.
“Release and catch” catalytic systems, Michelangelo Gruttadauria, Francesco Giacalone and Renato Noto, Green Chem., 2013, 15, 2608–2618, DOI: 10.1039/c3gc41132j
This review covers catch and release systems which do not use covalent bonding to a support. The concept is good in the sense that a homogeneous catalyst may have a single active site, whereas a heterogeneous catalyst may have several types of active sites. The systems work with a variety of metal catalysts, but activity decreases on repeating cycles. Metal leaching may be taking place. Further work is needed to make such systems practical for widespread use.