Kinetic Analysis of Hydrogen Transfer Route from Hot-Compressed 2-Propanol to Diphenyl Ether over NiCo/C Catalyst

Abstract

Transfer hydrogenolysis of diphenyl ether (DPE), a lignin model compound, was studied from the viewpoint of the reaction kinetics. Nearly 90% of DPE degradation and formation of aromatic products were demonstrated at 235 °C with the combination of 2-propanol (IPA) as a hydrogen-donating solvent and NiCo/C as a non-noble metal catalyst. Kinetic modeling of reaction results indicated the dominance of direct hydrogen transfer from IPA to DPE over the other possible pathway (indirect transfer via H2 gas). However, H2 gas formation from IPA, which was assumed to be inactive for DPE hydrogenolysis in the model, was also confirmed as a side reaction in a non-negligible amount. DPE hydrogenolysis and H2 formation activation energies were estimated to be 1.2 × 102 and 73 kJ/mol, respectively.