Hydrogen Doping into MoO3 Supports toward Modulated Metal-Support Interactions and Efficient Furfural Hydrogenation on Iridium Nanocatalysts.

Abstract

As promising supports, reducible metal oxides afford strong metal-support interactions to achieve efficient catalysis, which relies on their band states and surface stoichiometry. In this study, in situ and controlled hydrogen doping (H doping) by means of H2 spillover was employed to engineer the metal-support interactions in hydrogenated MoOx -supported Ir (Ir/H-MoOx ) catalysts and thus promote furfural hydrogenation to furfuryl alcohol. By easily varying the reduction temperature, the resulting H doping in a controlled manner tailors low-valence Mo species (Mo5+ and Mo4+ ) on H-MoOx supports, thereby promoting charge redistribution on Ir and H-MoOx interfaces. This further leads to clear differences in H2 chemisorption on Ir, which illustrates its potential for catalytic hydrogenation. As expected, the optimal Ir/H-MoOx with controlled H doping afforded high activity (turnover frequency: 4.62 min-1 ) and selectivity (>99 %) in furfural hydrogenation under mild conditions (T=30 °C, PH2 =2 MPa), which means it performs among the best of current catalysts.