Furfural hydrogenation over carbon-supported copper

Furfural hydrogenation over copper dispersed on three forms of carbon - act ivated carbon, diamond and graphitized fibers - were studied. Only hydrogen ation of the C=O bond to form either furfuryl alcohol or 2-methyl furan occ urred at temperatures from 473 to 573 K. Reduction at 573 K gave the most a ctive catalysts, all three catalysts had activation energies of 16 kcal/mol , and turnover frequencies were 0.018-0.032 s(-1) based on the number of Cu -0 + Cu+ sites, which were counted by N2O adsorption at 363 K and CO adsorp tion at 300 K, respectively. The Cu/activated carbon catalyst showed no dea ctivation during 10 h on stream, in contrast to the other two catalysts. A simple Langmuir-Hinshelwood model invoking two types of sites was able to f it all kinetic data quite satisfactorily, thus it was consistent with the p resence of both Cu-0 and Cu+ sites.