<scp> RuO <sub>2</sub> </scp> as promoter in <scp> Pt‐RuO <sub>2</sub> ‐ </scp> nanostructures/carbon composite, a <scp>pH</scp> ‐universal catalyst for hydrogen evolution/oxidation reactions
Sonali Panigrahy, Rajib Samanta, Prajnashree Panda, Ranjit Mishra, Sudip Barman
Abstract
The development of new catalysts for Hydrogen evolution reaction/Hydrogen oxidation reaction (HER/HOR) is of crucial importance for the commercialization of Proton-exchange membrane/Anion-exchange membrane-based renewable technologies. The sluggish HER/HOR kinetic (in base) and poor HER/HOR stability (in acid) of commercial Pt/C are the main obstacles. Interface engineering in multi-component nanostructures is a method for enhanced electrochemical performances. We report interfaces-engineered RuO2-Pt/C as a pH-independent catalyst for Hydrogen oxidation reaction/Hydrogen evolution reaction applications. The Hydrogen oxidation reaction/Hydrogen evolution reaction activity of RuO2-Pt/C is one order magnitude higher than commercial Pt/C in base and 2.5-fold higher in acid. It shows excellent stability in acid and base. It exhibits excellent pH tolerant HOR behavior. The i0,m of RuO2-Pt/C in the base is ~1833 A.g−1RuPt which is 8-fold higher than commercial Pt/C. The RuO2 in RuO2-Pt/C makes it more active toward HER/HOR in base. Although it has similar activity in acid, its basic activity is 29-fold higher than Ru-Pt-NPs/C. Hydrogen binding energy and OH binding energy are two equivalent descriptors for HOR/HER in base. HOR/HER activity of this catalyst in different 0.1 M electrolyte decreases in the sequence of Li+ > Na+ > K+ but improved HER and decreased HOR is observed with increasing Li+ ions. The [(H2O)x-AM+-(OH)ad] in double-layer influences HOR/HER performance of RuO2-Pt/C. This catalyst has great potential for application in PEM/AEM-based devices.