State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China.
Angew Chem Int Ed Engl. 2023 Jun 12;62(24):e202217337. doi: 10.1002/anie.202217337. Epub 2023 May 8.
Electrocatalytic nitrate reduction sustainably produces ammonia and alleviates water pollution, yet is still challenging due to the kinetic mismatch and hydrogen evolution competition. Cu/Cu O heterojunction is proven effective to break the rate-determining NO -to-NO step for efficient NH conversion, while it is unstable due to electrochemical reconstruction. Here we report a programmable pulsed electrolysis strategy to achieve reliable Cu/Cu O structure, where Cu is oxidized to CuO during oxidation pulse, then regenerating Cu/Cu O upon reduction. Alloying with Ni further modulates hydrogen adsorption, which transfers from Ni/Ni(OH) to N-containing intermediates on Cu/Cu O, promoting NH formation with a high NO -to-NH Faraday efficiency (88.0±1.6 %, pH 12) and NH yield rate (583.6±2.4 μmol cm h ) under optimal pulsed conditions. This work provides new insights to in situ electrochemically regulate catalysts for NO -to-NH conversion.
电催化硝酸盐还原可持续地生产氨并减轻水污染，但由于动力学不匹配和析氢竞争，仍然具有挑战性。Cu/CuO 异质结已被证明可有效打破决定氨转化效率的 NO 到 NO 步骤，但由于电化学重构，其并不稳定。在这里，我们报告了一种可编程脉冲电解策略，以实现可靠的 Cu/CuO 结构，其中 Cu 在氧化脉冲期间被氧化为 CuO，然后在还原时再生 Cu/CuO。与 Ni 合金化进一步调节了氢的吸附，其从 Ni/Ni(OH)转移到 Cu/CuO 上的含 N 中间体，在最佳脉冲条件下，以高的 NO 到 NH 的法拉第效率（88.0±1.6%，pH 12）和 NH 生成速率（583.6±2.4 μmol·cm -2 ·h -1 ）促进 NH 形成。这项工作为原位电化学调节 NO 到 NH 转化催化剂提供了新的见解。
