Dual-Metal Electron Pump Engineered Platinum-based HOR Catalysts for Ammonia-tolerant Hydrogen Sensing

Electrochemical hydrogen sensors are attractive for hydrogen detection owing to their high sensitivity, rapid response, and low energy consumption, offering great potential for safety monitoring in complex environments. However, the anodic HOR catalysts are highly susceptible to poisoning by interfering species such as ammonia, posing a critical challenge to the development of robust hydrogen sensors for ammonia-containing environments. Since binary transition metal elements are promising for further optimizing the HOR performance of platinum compared to single transition metals, metal salts with different combinations were dispersed on XC-72 by rotary evaporation here. After wet impregnation, FeCo-Pt, FeMn-Pt, CoMn-Pt, and Fe-Pt, were obtained by heat treatment under H2/Ar mixed gas. In this strategy, Fe and Co form an FeCo alloy during heat treatment. Compared to single-element doping, the alloyed transition metal acted as “dual-metal electron pump” further optimizes the electronic structure of Pt, thereby constructing a highly efficient composite catalyst system. This effective regulation of the electronic structure significantly enhances the electron transfer capability of Pt, ultimately achieving simultaneous improvements in the catalyst’s HOR activity and ammonia resistance, thereby enabling efficient hydrogen sensing with strong resistance to disturbance.