Two-dimensional MXene supported Ru-Cr(OH)x clusters as an efficient electrocatalyst for hydrogen oxidation reaction

Abstract

The development of high-performance non-platinum catalysts remains a key challenge for the practical application of anion-exchange membrane fuel cells due to the sluggish kinetics response of the hydrogen oxidation reaction (HOR) in alkaline electrolytes. Herein, we report an outstanding HOR electrocatalyst using a facile one-step method with the two-dimensional double transition metal MXene (Mo2TiC2Tx) as a carrier mixed with metallic ruthenium and Cr(OH)x clusters (Ru-Cr(OH)x/MXene). Specifically, the as-prepared Ru-Cr(OH)x/MXene electrocatalyst exhibits a high apparent kinetic current (jk) of 18.32 mA cm−2 and exchange current (j0) of 1.64 mA cm−2 at an overpotential of 50 mV, respectively, which are 4.74 and 1.46 times as high as those of Pt/C catalyst. Additionally, mechanism experiments indicated that the Ru-Cr(OH)x/MXene electrocatalyst could attenuate the adsorption of hydrogen intermediate (Had) and enhance the adsorption of hydroxyl species (OHad) to promote CO oxidation, which resulted in a significant increase in the HOR activity and enhanced tolerance to CO. Furthermore, combining theoretical studies via density functional theory calculations, our work confirm that the interaction effect of each components of Ru-Cr(OH)x/MXene can optimize the binding energy of the Had and OHad for the HOR. This work develops a new approach to design of HOR electrocatalyst with MXene-based materials.