Zou Zhi, Wu Lei, Yang Fangqi, Cao Chenliang, Meng Qiangguo, Luo Junhui, Zhou Weizhen, Tong Zhikun, Chen Jingwen, Chen Shixia, Zhou Shaodong, Wang Jun, Deng Shuguang
School of Resource Environmental and Chemical Engineering, Nanchang University, Jiangxi, Nanchang, 330031, P. R. China.
College of Chemical and Biological Engineering, Zhejiang University, Zhejiang, Hangzhou, 310058, P. R. China.
ChemSusChem. 2022 Mar 22;15(6):e202200127. doi: 10.1002/cssc.202200127. Epub 2022 Feb 15.
Electroreduction of N to NH at ambient conditions using renewable electricity is promising, but developing efficient electrocatalysts is still challenging due to the inertness of N≡N bonds. Layer double hydroxides (LDHs) composed of first-row transition metals with empty d-orbitals are theoretically promising for N electroreduction (NRR) but rarely reported. Herein, hollow NiCo-LDH nanocages with different Ni/Co ratios were prepared, and their electronic structures and atomic arrangements were critical. The synergetic mechanisms of Ni and Co ions were revealed, and the optimized catalytic sites were proposed. Besides, in-situ Raman spectroscopy and N isotopic labeling studies were applied to detect reaction intermediates and confirm the origin of NH . As a result, high NH yield of 52.8 μg h mg and faradaic efficiency of 11.5 % were obtained at -0.7 V, which are top-ranking among Co/Ni-based NRR electrocatalysts. This work elucidates the structure-activity relationship between LDHs and NRR and is instructive for rational design of LDH-based electrocatalysts.
在环境条件下利用可再生电力将N电还原为NH具有广阔前景，但由于N≡N键的惰性，开发高效的电催化剂仍然具有挑战性。由具有空d轨道的第一排过渡金属组成的层状双氢氧化物（LDHs）在理论上对N电还原（NRR）具有前景，但鲜有报道。在此，制备了具有不同Ni/Co比的中空NiCo-LDH纳米笼，其电子结构和原子排列至关重要。揭示了Ni和Co离子的协同机制，并提出了优化的催化位点。此外，采用原位拉曼光谱和N同位素标记研究来检测反应中间体并确认NH的来源。结果，在-0.7 V时获得了52.8 μg h mg的高NH产率和11.5%的法拉第效率，在基于Co/Ni的NRR电催化剂中名列前茅。这项工作阐明了LDHs与NRR之间的构效关系，对基于LDH的电催化剂的合理设计具有指导意义。
