Engineering the highly efficient heterogeneous catalyst based on PdCu nanoalloy and nitrogen-doped Ti3C2Tx MXene for ethanol electrooxidation

Abstract

Improving the electrocatalytic performance by modulating the surface and interface electronic structure of noble metals is still a research hotspot in electrocatalysis. Herein, we prepared the heterogeneous catalyst based on the well-dispersed PdCu nanoalloy and the N-doped Ti3C2Tx MXene support (PdCu/N-Ti3C2Tx) via in situ growth of PdCu nanoparticles on the fantastic N-Ti3C2Tx sheets. By exploring the electrocatalytic properties of ethanol oxidation reaction (EOR), the composition optimized Pd1Cu1/N-Ti3C2Tx delivers higher mass activity/specific activity/intrinsic activity (2200.7 mA mgPd-1/13.1 mA cm−2/2.2 s−1), anti-poisoning ability and stability than those of Pd/N-Ti3C2Tx, Pd1Cu1/Ti3C2Tx and commercial Pd/C, which can be attributed to the modified surface electronic features of Pd by the participation of Cu atoms and N-Ti3C2Tx MXene, as well as the “metal-carrier” effect between the PdCu nanoalloy and N-Ti3C2Tx heterogeneous interface. Furthermore, the conductivity of N-Ti3C2Tx MXene can be improved by N-doping, and the abundant terminal groups (-O, –OH, -F and N) on the N-Ti3C2Tx surface can promote the electron exchange between PdCu and N-Ti3C2Tx. This work provides an effective strategy for engineering heterogeneous electrocatalysts for enhanced electrocatalytic EOR by adjusting the interfacial electronic structure of noble metals.