Multi-site activation in metal-doped CuPd alloy catalysts enhances nitrate electroreduction to ammonia

Abstract

The electrochemical nitrate reduction reaction (NO₃RR) represents an environmentally friendly pathway for ammonia production and nitrate purification while the development of efficient NO₃RR catalysts is crucial to achieve a high performance. In this study, a series of transition metal-doped CuPd alloy (TM-CuPd, TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni) were explored as NO₃RR catalysts through density functional theory calculation. Multi-site active center was designed to explore the structure-performance relation on TM-CuPd catalysts for NO₃RR. Notably, Mn–CuPd was proposed to provide a unique combination of high activation ability for NO₃⁻ and robust protonation ability for intermediates, leading to excellent catalytic performance with the reaction free energy change of 0.14 eV for the potential limiting step of Mn–CuPd in the NO₃RR. In essence, the excellent activity of Mn–CuPd catalyst benefits from the highly flexible adsorption behavior of intermediates on the multi-site active center, which effectively optimizes the reaction pathway.