Zhou Lixue, Feng Daming, Li Zhiqiang, Lv Zhenghao, Li Hui, Ge Chunhua, Zhang Xiangdong, Ma Tianyi
College of Chemistry, Liaoning University, Chongshan Middle Road, Huanggu District, Shenyang, Liaoning 110036, P. R. China.
Centre for Atomaterials and Nanomanufacturing (CAN), School of Science, RMIT University, Melbourne, Victoria 3000, Australia.
ACS Appl Mater Interfaces. 2025 Jul 2;17(26):38050-38061. doi: 10.1021/acsami.5c06917. Epub 2025 Jun 17.
To kill two birds in one stone, electrocatalytic reduction of nitrate (NO) offers a mild and reliable approach for wastewater denitrification and a green pathway for ammonia (NH) production. Despite the complex proton-coupled electron transfer process in NO reduction, efficient NH production has been challenging. In this study, high-entropy multivalent chalcogenides (HEMCs) were synthesized, exhibiting a synergistic catalytic effect for enhanced electrochemical performance. The highest Faraday efficiency of 92.3% and NH yield rate of 5.67 mg h cm were achieved at -0.6 and -0.8 V versus reversible hydrogen electrode (V vs RHE) under the catalysis of HEMC with Fe, Cu, Co, Cr, Zr, Ni, and Bi (molar ratio 1:1:1:1:1:1:1), denoted as F3CZNB. Comparatively, senary and quinary HEMCs, namely, F3CZN and F3CZ, were also synthesized. Characterization and catalytic performance analyses revealed that Fe and Cu primarily contributed to the catalytic activity, while NH selectivity and electrode stability were attributed to the stoichiometric composition of the metals. Ni further enhanced conversion of NO to NH by its hydrophilicity, and Bi improved conductivity and durability with d-p interaction with transition metals. The NO reduction reaction pathway was confirmed by detecting intermediates (*NO, *NO, *NHOH, *NH, and *NH) on the catalyst surface using in situ Fourier transform infrared spectroscopy (in situ FT-IR) and electrochemical differential mass spectrometry (DEMS). A Zn-NO battery assembled with F3CZNB demonstrated an energy density of 6.45 mW cm, highlighting the potential of F3CZNB for energy conversion devices. This study sheds light on a novel protocol for synthesizing multivalent chalcogenides with potent electrocatalytic activity.
一石二鸟的是，硝酸盐（NO）的电催化还原为废水脱氮提供了一种温和且可靠的方法，同时也为氨（NH₃）的生产开辟了一条绿色途径。尽管NO还原过程中存在复杂的质子耦合电子转移过程，但高效生产NH₃一直具有挑战性。在本研究中，合成了高熵多价硫族化物（HEMCs），其表现出协同催化作用，可增强电化学性能。在以铁、铜、钴、铬、锆、镍和铋（摩尔比1:1:1:1:1:1:1）为成分的HEMC（记为F3CZNB）催化下，相对于可逆氢电极（V vs RHE），在-0.6 V和-0.8 V时分别实现了92.3%的最高法拉第效率和5.67 mg h⁻¹ cm⁻²的NH₃产率。相比之下，还合成了六元及五元的HEMCs，即F3CZN和F3CZ。表征和催化性能分析表明，铁和铜主要促成了催化活性，而NH₃选择性和电极稳定性则归因于金属的化学计量组成。镍因其亲水性进一步提高了NO向NH₃的转化，铋通过与过渡金属的d-p相互作用改善了导电性和耐久性。通过原位傅里叶变换红外光谱（原位FT-IR）和电化学差分质谱（DEMS）检测催化剂表面的中间体（*NO、*NO₂、*NHOH、NH₂和NH₃），证实了NO还原反应途径。用F3CZNB组装的锌-NO电池的能量密度为6.45 mW cm⁻²，突出了F3CZNB在能量转换装置方面的潜力。这项研究为合成具有强大电催化活性的多价硫族化物提供了一种新方案。
