Lewis Acidic VOx Engineered PdAu Nanocatalysts for Efficient Formic Acid Dehydrogenation

Abstract

The development of high-performance catalysts for formic acid (FA) dehydrogenation is of extreme significance to the successful production of hydrogen under ambient conditions. Despite some encouraging progress, their activity is still unsatisfied than needed. In this work, it is presented that Lewis acidic VO_x sites engineered ultrafine PdAu nanoclusters (PdAu-VO_x) perform perfectly for hydrogen production from FA dehydrogenation. Strikingly, the best catalyst — PdAu-VO_x embed in amino-functionalized hollow mesoporous support (PdAu-VO_x/NHMS) discloses an impressive initial turnover frequency of 14155 h⁻¹ and a low activation energy of 31.2 kJ mol⁻¹ without additives at room temperature, and maintains 100% selectivity and conversion in the tenth cycle reaction. Mechanistic investigations illustrate that VO_x species can serve as the Lewis acid sites, which not only regulate the adsorption strength of reactant and intermediate on PdAu, but also reinforce the C─H bond activation within FA molecule, thereby promoting the reaction kinetics for efficient hydrogen production. This work thus provides a strategy for the development of new-style heterogeneous catalysts with Lewis acid-base sites applied to a variety of energy-related catalytic reactions.