Anion assisted completely reconfigured manganese oxides with optimal proton adsorption for boosting acidic hydrogen evolution reaction

Abstract

The optimal proton adsorption design of non-noble metal based catalysts is critical to the realization of efficient hydrogen evolution reactions (HER) in acidic media, but it is also challenging. Herein, sulfur anion-assisted completely reconfigured MnO x (R-S-MnO x -CC) with self-supported nanostructure was prepared on carbon cloth by in situ phase transformation method. The reconfiguration process results in spinel-structured Mn 3 O 4 which can enhance charge transport and expose more active sites through charge disproportionation. The theoretical calculation indicates that the reconfiguration can increase the electron state density of the Mn d band near the Fermi level, promote the right shift of the d -band center, enhance the electron transport capacity of the catalyst to achieve the optimal H + adsorption. The R-S-MnO x -CC catalyst has excellent acidic HER performance with an overpotential of only 43 mV and 234 mV at 10 mA cm −2 and 400 mA cm −2 , respectively, a low charge transfer resistance R ct (0.29 Ω) and stably maintained for 100 h without decay (∼300 mA cm −2 ). This strategy provides a feasible way to design efficient and stable non-noble metal-based electrocatalysts for the HER industrialization of proton exchange membrane (PEM) water electrolyzers.