Tetrahexahedral PdRh nanocrystals with tunable composition as a highly efficient electrocatalyst for ethylene glycol oxidation

Abstract

Optimization of the structure and composition is critical to obtain excellent electrocatalytic performance of palladium-based electrocatalysts, which have received extensive attention in the past few decades. However, the synthesis of PdRh nanocrystals (NCs) enclosed by high-index facets with different compositions is still rarely reported. Herein, alloy tetrahexahedral (THH) PdRh NCs enclosed by {11 4 0} facets with tunable composition were prepared for the first time by an electrochemical square-wave potential method. The as-prepared PdRh NCs exhibit high catalytic activity for ethylene glycol (EG) electrooxidation. The catalytic activity highly depends on the alloy composition, and THH Pd_86.9Rh_13.1 NCs exhibit the highest catalytic activity, which is 2.0 and 11.1 times higher than that of THH Pd NCs and commercial Pd/C, respectively. In situ FTIR spectroscopic studies of THH Pd_86.9Rh_13.1 NCs and THH Pd NCs revealed that the introduction of Rh can enhance the capability of cleaving the C–C bond. This study indicates that the synergetic effect of high-index facets with the alloy electronic structure is promising for the preparation of high performance electrocatalysts.