Highly Efficient Ir–CoO_x Hybrid Nanostructures for the Selective Hydrogenation of Furfural to Furfuryl Alcohol

Decoration of noble metals with transition-metal oxides has been intensively studied for heterogeneous catalysis. However, controllable syntheses of metal–metal oxide heterostructures are difficult, and elucidation of such interfaces is still challenging. In this work, supported IrCo alloy nanoparticles are transformed into supported Ir–CoOx close-contact nanostructures by in situ calcination and following selective reduction. Relative to Ir/Al2O3, Ir–CoOx/Al2O3 shows greatly enhanced activities for the hydrogenation of furfural derivatives to the corresponding furfuryl alcohol derivatives with more than 99% selectivity and demonstrates significantly improved activities and selectivity for hydrogenations of α,β-unsaturated aldehydes to α,β-unsaturated alcohols. The modification of Ir surfaces with CoOx prevents Ir nanoparticles from growing, achieving high thermal and catalytic stabilities. Theoretic calculation suggests that the better catalytic performance of Ir–CoOx/Al2O3 is ascribed to the Ir–CoOx interaction, which promotes the absorption of furfural as well as desorption of furfuryl alcohol, resulting in enhanced catalytic activities.