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

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 degrees 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 H-2 gas). However, H-2 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 H-2 formation activation energies were estimated to be 1.2 x 10(2) and 73 kJ/mol, respectively.