Carbon Nanocage Confining CuCo Bimetallic Interface with Low Nitrate Adsorption Energy for Highly Efficient Electrochemical Ammonia Synthesis
- Resource Type
- Article
- Authors
- Cheng, Jun; Dai, Guorun; Sun, Weifu; Yang, Xian; Xia, Rongxin; Xu, Yang; Mao, Yuxiang
- Source
- Energy & Fuels; February 2024, Vol. 38 Issue: 3 p2501-2510, 10p
- Subject
- Language
- ISSN
- 08870624; 15205029
This work aimed to improve the Faraday efficiency and formation rate of ammonia with a low reaction potential in the electroreduction of nitrate. For this purpose, CuCo bimetallic interface-rich catalysts confined in porous nitrogen-doped carbon nanocages (CuCo/NC) were designed. Results of in situ Fourier transform infrared spectroscopy suggested that the reaction path followed the sequence NO3–→ *NO3→ *NO2→ *NO → *NOH → *NH2OH → *NH3→ NH3. Density functional theory calculations revealed that the adsorption of nitrate over the CuCo bimetallic interface was thermodynamically favorable. CuCo bimetallic interface changed the rate-determining step of nitrate reduction at Cu sites from nitrate adsorption to *NO hydrogenation and promoted the continuous hydrogenation of nitrogen-related intermediates. Over the CuCo/NC catalyst, Faraday efficiency and formation rate of ammonia were 95.1% (at −0.59 V vs reversible hydrogen electrode (RHE)) and 9110.8 μg h–1mgcat.–1(at −0.79 V vs RHE), which were higher than those over Cu/NC and Co/NC catalysts.