Porous carbon supported PtPd alloy nanoparticles derived from N-heterocyclic carbene bimetal complex as efficient bifunctional electrocatalysts

Abstract

Pyrolysis of metal complexes has been recently reported as a facile and economic method for the design and large-scale synthesis of carbon supported metal materials. In particular, N-heterocyclic carbenes (NHCs) possess obvious advantages such as the strong binding to many metals, high stability and synthetic accessibility as compared to other ligands. In this work, the bimetal-NHC complex is pyrolyzed for the first time to synthesize the carbon supported PtPd alloy electrocatalyst (PtPd/CKN) for oxygen reduction reaction and hydrogen evolution reaction. The coordination of metal with NHC ligands strengthened the metal-support interactions, resulting in the stabilization of metal nanoparticles against agglomerations under high-temperature synthesis and catalytic reaction conditions. As a result, the optimal Pt2Pd3/CKN material possesses the uniform distribution of metal nanoparticles with the size of 2–4 nm and exhibits better electrocatalytic activity than commercial Pt/C. More importantly, the strong metal-support interaction effectively enhanced the durability of the alloy electrocatalyst with only 3 mV of negative shift after 10,000 cycles.