Tailoring asymmetric RuCu dual-atom electrocatalyst toward ammonia synthesis from nitrate
Kaiyuan Liu, Zhiyi Sun, Xingjie Peng, Xudong Liu, Xiao Zhang, Boran Zhou, Kedi Yu, Zhengbo Chen, Qiang Zhou, Fang Zhang, Yong Wang, Xin Gao, Wenxing Chen, Pengwan Chen
Abstract
Atomically dispersed Ru-Cu dual-atom catalysts (DACs) with asymmetric coordination are critical for sustainable ammonia production via electrochemical nitrate reduction (NO3RR), but their rational synthesis remains challenging. Here, we report a pulsed discharge strategy that injects a microsecond pulse current into ruthenium (Ru) and copper (Cu) precursors supported by nitrogen-doped graphene aerogels (NGA). The atomically dispersed Ru and Cu dual atoms anchor onto nanopore defects of NGA (RuCu DAs/NGA) through explosive decomposition of the metal salt nanocrystals. The catalyst achieves 95.7% Faraday efficiency and 3.1 mg h−1 cm−2 NH3 yield at −0.4 V vs. RHE. In situ studies reveal an asymmetric RuN2-CuN3 active-site dynamic evolution during NO3RR. Density functional theory calculations demonstrate that asymmetric RuN2CuN3/C structure synergistically optimizes intermediate adsorption and reduces energy barriers of key steps. The pulsed discharge enables ultrafast synthesis of various DACs (e.g., PtCu, AgCu, PdCu, FeCu, CoCu, NiCu) with tailored coordination environments, offering a general-purpose strategy for the precise preparation of atomically dispersed dual-atom catalysts, which are traditionally challenging to synthesize. Nitrate electroreduction to ammonia offers a sustainable route, but designing efficient catalysts remains challenging. Here, the authors develop a pulsed discharge strategy to synthesize dual atom catalysts with asymmetric active sites, achieving high ammonia production efficiency and stability.