Pivotal role of H2 in the isomerisation of isosorbide over a Ru/C catalyst

Abstract

Isosorbide isomerisation is a known reaction that can proceed over Ru and Ni-based heterogeneous catalysts. As a rule, an exogenous H₂ pressure (40–100 bar) is required, even though H₂ does not participate stoichiometrically in the reaction. By marrying experiments with DFT computations, we ascribe the role of H₂ in isosorbide isomerisation to a coverage effect on the catalyst surface. We demonstrate the possibility of conducting the reaction at a low H₂ pressure either in the presence of an inert gas to increase H₂ solubility in an underlying solvent or using 2-propanol as a hydrogen donor. This might benefit the economy and safety of a potential industrial process.