Regulating Rh-based rare earth nanoalloy electrocatalysts by scandium, yttrium for accelerated hydrogen evolution kinetics

The construction of rare earth (RE) alloy catalysts offers a route to harness the unique electronic structure of RE. Within the alloy, RE can fine-tune the electronic configuration of the active element, such as rhodium (Rh), via the ligand effect, optimizing the electrochemical reaction pathway. However, the challenging negative reduction potential of RE has impeded the progress in developing RE alloys, particularly nanoalloy catalysts. In this study, Rh 3 Sc/C and Rh 3 Y/C nanoalloys were synthesized using a sodium vapor reduction strategy for application as hydrogen evolution reaction (HER) catalysts. Electrochemical tests reveal that Rh-RE alloy catalysts exhibit significantly improved electrocatalytic activity in 1 mol/L KOH. Notably, Rh 3 Y/C demonstrates exceptional HER performance, achieving a low overpotential of only 31 mV at 10 mA/cm 2 , surpassing the 50 mV observed for Rh/C. Furthermore, the current density of Rh 3 Y/C at an 80 mV overpotential is 3.9 times that of Rh/C. This study sheds light on the remarkable catalytic potential of Rh-RE alloys, paving the way for the future expansion of RE nanoalloy systems.