Cellulose from biomass is an abundant and renewable resource with a high potential for the sustainable production of fuels and chemicals. Combinations of acid-catalyzed hydrolysis with metal-catalyzed hydrogenation/hydrogenolysis enable the production of a wide variety of platform chemicals. Catalysts system based on noble metals (Pt, Ir, Rh, Pd and Ru) and non-noble metals (Cu, Ni, W) are currently under intensive investigation. Of the noble metals, Ru is a highly promising candidate due to low cost, high activity and high stability under acidic conditions. Ru-catalyzed hydrolytic-hydrogenation of cellulose combines hydrolysis with hydrogenation in a one-pot fashion and directly gives sorbitol as the main product. By variation of the reaction conditions follow-up reactions to short chain polyols, isosorbide and alkanes are also possible, demonstrating the high versatility of Ru-based catalysts (Image 1). Significant advancements have been achieved in the selective preparation of target products; however, insight into these complex reactions remains limited. A few studies have provided insight into the reaction mechanism by studying the resulting product mixture and several fundamentally different mechanisms have been proposed to date. Still definitive proofs for the elementary transformations on the catalyst surface remain elusive. Therefore we have studied the Ru catalysed hydrogenolysis of polyols in great detail . Here we present an overview of this work which includes : - elucidation of the reaction network of polyol degradation (Image 2) - kinetic analysis of the product mixture to obtain the apparent activation energies - periodic DFT calculations on model reactions - first attempts at rational catalyst design to suppress undesired side reactions.

Ru-catalyzed hydrogenolysis of polyols: From molecular understanding toward rational catalyst design

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.