Computational study on graphdiyne supported PdxCuy clusters as potential catalysts for formic acid dehydrogenation

Abstract

Designing low-cost and efficient catalysts for formic acid dehydrogenation (FAD) is crucial to facilitate the practical applications of formic acid as a hydrogen carrier. Using density functional theory calculations, we designed nine graphdiyne-supported Pd/Cu single-, double-, and triple-atom catalysts, investigating their stability and formic acid dehydrogenation performance. The results indicate that as the number of active metal sites increases, the catalytic activity for formic acid dehydrogenation improves, i.e., M3@GDY > M2@GDY > M1@GDY (M = Pd/Cu). Moreover, a synergistic effect between Pd and Cu atoms is observed in PdxCu3-x@GDY, where the activity sequence of triple-atom catalysts was Pd1Cu2@GDY > Pd2Cu1@GDY > Pd3@GDY > Cu3@GDY. Particularly, Pd1Cu2@GDY exhibits superior FAD catalytic activity and hydrogen selectivity, presenting a potential novel formic acid dehydrogenation catalyst. Electronic structure analysis indicates that the band center difference Δε (Δε = εd - εp) serves as an assessment descriptor for formic acid dehydrogenation activity. Microkinetic analysis further confirms the performance of TACs predicted by DFT results, and shows that all TACs have good H2 selectivity even at a high temperature.