Cation in Imidazolium-Based Ionic Liquids Promoting H-Spillover in Metal Oxide Supported Catalyst for Selective Catalytic Hydrogenolysis

The introduction of an organic ligand modifier in heterogeneous catalytic systems has demonstrated efficiency in enhancing the catalytic performance, although the specific role of the ligand remains ambiguous. The selective ring-opening hydrogenation of furfuryl alcohol (FOL) offers a promising approach for synthesizing 1,2-pentanediol (1,2-PeD) in contrast to conventional fossil-based methods. We observed a significant enhancement in the selective hydrogenolysis of FOL to 1,2-PeD facilitated by ionic liquids. Experimental data revealed that Pt/CeO2-[C4mim]BF4 exhibited a remarkable 73.9% selectivity for 1,2-PeD, while Pt/CeO2 displayed only 12.5% selectivity. Additionally, our results indicated a correlation between the performance of ionic liquids and the properties of the support. Specifically, the catalyst with a reducible support demonstrated a more pronounced enhancement in 1,2-PeD selectivity, while it did not improve selectivity over the Pt/C catalyst. Mechanistic investigations suggested that the presence of the ionic liquids promoted hydrogen spillover, resulting in the reduction of Ce4+ to Ce3+ and an increase in oxygen vacancy sites, facilitating the production of 1,2-PeD. This study unveils the first correlation between the enhancement from the organic ligand modification of heterogeneous catalysts and the properties of the carrier, shedding light on the underlying mechanism and providing a new avenue for regulating heterogeneous catalyst performance.