HCOOH Dissociation Over the Core-Shell M@Pd Bimetallic Catalysts: Probe into the Effect of the Core Metal Type on the Catalytic Performance

Abstract The core-shell bimetallic catalysts have exhibited unique catalytic performance due to the bimetallic synergetic effect. In this work, the catalytic activity and selectivity of HCOOH dissociation on the Mcore@Pdshell(M=Cu, Au, Co, Ni, Ag, Al) catalysts are investigated to reveal the effect of the core metal on the shell Pd catalytic performance. Density functional theory calculations with microkinetic modeling are used. The results showed that compared to the Pd catalyst, M@Pd(M=Au, Co, Ni, Ag) catalysts are highly selective to CO2 formation, while Al@Pd is favorable for CO formation. Especially, Ag@Pd catalyst not only presents the best activity and selectivity toward CO2 generation, but also decreases CO adsorption ability to inhibit its poisoning and reduce noble Pd usage. The analysis of the electronic properties about the average Bader charge and d-band center corresponding to the shell Pd identify the function of the core metal type in adjusting the shell Pd catalytic performance toward HCOOH dissociation, in which the ligand effect caused by charge transfer between the core metal to the shell Pd plays a key role. This study provides valuable information for the improved performance of the core-shell bimetallic catalysts by altering the types of core metal.