Jia Fangshuo, Zhang Yujuan, Zhang Xiutang, Hu Tuoping
Department of Chemistry, School of Chemistry and Chemical Engineering, North University of China, Taiyuan 030051, PR China.
Department of Chemistry, School of Chemistry and Chemical Engineering, North University of China, Taiyuan 030051, PR China.
J Colloid Interface Sci. 2025 Jan;677(Pt B):597-607. doi: 10.1016/j.jcis.2024.08.086. Epub 2024 Aug 14.
Methanol oxidation reaction (MOR) and urea oxidation reaction (UOR) can be utilized as effective alternatives to the anodic oxygen evolution reaction (OER) in overall water-splitting. Nevertheless, the development of cost-effective, highly efficient and durable electrocatalysts for MOR and UOR remains a significant challenge. Herein, the Ohmic junction (Ni-CuCoN@CC) comprising CuCoN nanosheets and Ni nanoparticles anchored on carbon cloth (CC) was successfully synthesized via a two-step hydrothermal process followed by pyrolysis. The Ni-CuCoN@CC demonstrates exceptional performance in both MOR (1.334 V@10 mA cm) and UOR (1.335 V@10 mA cm), coupled with outstanding durability, maintaining 88.70 % current density for MOR and 88.92 % for UOR after a rigorous 50-h stability test. Furthermore, the Ni-CuCoN@CC demonstrates a high selectivity for oxidizing methanol to formic acid, achieving Faraday efficiencies exceeding 90 % at various current densities in the context of MOR. The outstanding performance of Ni-CuCoN0@CC in terms of MOR and UOR either surpasses or closely approaches the levels reported in previous literature, primarily due to the synergistic effect resulting from the Ohmic junction: in this system, Ni serves as the principal active component, Co augments catalytic activity and diminishes onset potential, while Cu enhances long-term durability. Moreover, CuCoN nanosheets effectively modulate electronic structure and optimize the morphology of Ni, leading to the exposure of numerous defects that provide a wealth of active sites for the reaction. Additionally, the exceptional hydrophilic and aerophobic surface promotes enhanced mass transfer. Density functional theory (DFT) calculations show that Ni-CuCoN@CC enhances reactant adsorption and product desorption, reducing energy barriers and expediting MOR and UOR kinetics.
甲醇氧化反应（MOR）和尿素氧化反应（UOR）可作为全水解中阳极析氧反应（OER）的有效替代反应。然而，开发用于MOR和UOR的具有成本效益、高效且耐用的电催化剂仍然是一项重大挑战。在此，通过两步水热法随后热解成功合成了由锚定在碳布（CC）上的CuCoN纳米片和Ni纳米颗粒组成的欧姆结（Ni-CuCoN@CC）。Ni-CuCoN@CC在MOR（1.334 V@10 mA cm）和UOR（1.335 V@10 mA cm）中均表现出优异的性能，同时具有出色的耐久性，经过严格的50小时稳定性测试后，MOR的电流密度保持88.70%，UOR的电流密度保持88.92%。此外，Ni-CuCoN@CC对将甲醇氧化为甲酸具有高选择性，在MOR的各种电流密度下法拉第效率超过90%。Ni-CuCoN0@CC在MOR和UOR方面的出色性能要么超过要么接近先前文献报道的水平，这主要归因于欧姆结产生的协同效应：在该体系中，Ni作为主要活性成分，Co增强催化活性并降低起始电位，而Cu提高长期耐久性。此外，CuCoN纳米片有效地调节电子结构并优化Ni的形态，导致大量缺陷暴露，为反应提供了丰富的活性位点。另外，优异的亲水性和气疏性表面促进了传质增强。密度泛函理论（DFT）计算表明，Ni-CuCoN@CC增强了反应物吸附和产物脱附，降低了能垒并加快了MOR和UOR动力学。
