Iodine-Modified Pt Nanoparticle Catalysts for the Selective Ring-Opening Hydrogenolysis of Furfuryl Alcohol to 1,2-Pentanediol

The regulation of metal-acid bifunctional sites is of great significance in heterogeneous catalysis. In this study, commercial Pt/Al2O3 catalysts were modified by ethyl iodide under reductive conditions to prepare I–Pt/Al2O3 catalysts with intimate metal-acid bifunctional sites for the selective hydrogenolysis of furfuryl alcohol to 1,2-pentanediol. Electron transfer from Pt nanoparticles to I results in the formation of a negatively charged I adatom on the positively charged Pt surface, which induces on-surface hydrogen spillover to form Pt(H–)–I(H+) metal-acid bifunctional sites under a hydrogen atmosphere. By modulating the I coverage, the ratio between metal and acid sites on the catalyst surface can be finely adjusted at the nanoscale, providing a tunable hydrogenolysis selectivity of th furan ring toward 1,2- or 1,5-pentanediol. The selectivity for 1,2-pentanediol was promoted from 17.2% over the initial Pt/Al2O3 catalyst to 67.0% over I–Pt/Al2O3 catalysts at full furfuryl alcohol conversion. The developed Pt–I catalyst with controllable metal-acid bifunctional sites holds great promise for the catalytic upgrading of biomass-derived molecules.