N-Coordinated Iridium–Molybdenum Dual-Atom Catalysts Enabling Efficient Bifunctional Hydrogen Electrocatalysis

Abstract

Achieving effective hydrogen evolution/oxidation reaction (HER/HOR) across a wide pH span is of critical importance in unlocking the full potential of hydrogen energy but remains intrinsically challenging. Here, we engineer the Ncoordinated Ir−Mo dual atoms on a carbon matrix by ultrafast high-temperature sintering, creating an efficient bifunctional electrocatalyst for both HER and HOR in both acidic and alkaline electrolytes. The optimized catalyst, Ir−Mo DAC/NC, demonstrates exceptional performance, with a significantly reduced HER overpotential of 11.3 mV at 10 mA/cm 2 and a HOR exchange current (i 0,m ) of 3972 mA/mg Ir in acidic conditions, surpassing the performance of Pt/C and Ir/C catalysts. In alkaline conditions, Ir− Mo DAC/NC also outperforms Pt/C, as evidenced by its low HER overpotential of 23 mV at 10 mA/cm 2 and a high i 0,m of 1308 mA/mg Ir . Furthermore, our catalyst exhibits remarkable stability in both acidic and alkaline environments. DFT calculations results reveal that the superior electrochemical performance of Ir−Mo DAC/NC arises from the electronic synergy between Ir and Mo pairs, which regulates the interaction between the intermediates and active sites. These findings present a promising strategy for the development of dual-atom catalysts (DACs), with potential applications in the polymer fuel cells and water electrolyzers.

Heteronuclear Dual Metal Atom Electrocatalysts for Water-Splitting Reactions

“…DACs can achieve effective HER across a wide pH span, outperforming the performance of Pt/C. Qu and co-workers prepared N-coordinated Ir-Mo DAC on a carbon matrix [71]. The as-prepared Ir-Mo DAC/NC has an overpotential of 11.3 mV at 10 mA cm −2 in 0.5 M H2SO4, surpassing that of Ir/C and Pt/C (Figure 6a).…”

“…The distinctive W-O-Mo-O-C configuration in W 1 Mo 1 -NG serves as the active site for HER, endowing the electrocatalyst with superior activity and stability.DACs can achieve effective HER across a wide pH span, outperforming the performance of Pt/C. Qu and co-workers prepared N-coordinated Ir-Mo DAC on a carbon matrix[71]. The as-prepared Ir-Mo DAC/NC has an overpotential of 11.3 mV at 10 mA cm −2 in 0.5 M H 2 SO 4 , surpassing that of Ir/C and Pt/C (Figure6a).…”

A synergic investigation of experimental and computational dual atom electrocatalysis for CO2 conversion to C1 and C2+ products

“…49 The type of support used greatly affects the overall activity of DACs; for example, Ir 1 Mo 1 DAC loaded on N-doped carbon favours the hydrogen evolution reaction (HER) while Ir 1 Mo 1 DAC loaded on a TiO 2 support catalyses the reverse process, hydrogen adsorption. 50,51 This is possible only because of the change in the dominant metal active site with respect to the support. Thus, using DACs for multi-intermediate reactions such as the eCO 2 RR seems logical and has been found to show better results in the formation of C 1 and C 2 products from CO 2 (Scheme 1).…”