Creating affordable electrocatalysts and understanding the real-time catalytic process of the urea oxidation reaction (UOR) are crucial for advancing urea-based technologies. Herein, a Cu–Ni based selenide electrocatalyst (CuSe_y/NiSe_x/NF) was created using a hydrothermal technique and selenization treatment, featuring a heterogeneous interface rich in Cu_2–xSe, Cu₃Se₂, Ni₃Se₄, and NiSe₂. This catalyst demonstrated outstanding urea electrooxidation performance, achieving 10 mA cm^–2 with just 1.31 V and sustaining stability for 96 h. Through in-situ Raman spectroscopy and ex-situ characterizations, it is discovered that NiOOH is formed through surface reconstruction in the UOR process, with high-valence Ni serving as the key site for effective urea oxidation. Moreover, the electrochemical analysis revealed that CuSe_y had dual effects. An analysis of XPS and electrochemical tests revealed that electron transfer from CuSe_y to NiSe_x within the CuSe_y/NiSe_x/NF heterostructure enhanced the UOR kinetics of the catalyst. Additionally, according to the in-situ Raman spectroscopy findings, the existence of CuSe_y facilitates a easier and faster surface reconstruction of NiSe_x, leading to the creation of additional active sites for urea oxidation. More significantly, this work provides an excellent “precatalyst” for highly efficient UOR, along with an in-depth understanding of the mechanism behind the structural changes in electrocatalysts and the discovery of their true active sites.

中文翻译：

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界面可在异质结构 CuSey/NiSex 电催化剂中实现更快的表面重建，以实现尿素氧化


创造经济实惠的电催化剂并了解尿素氧化反应 (UOR) 的实时催化过程对于推进尿素技术至关重要。在此，利用水热技术和硒化处理制备了一种 Cu-Ni 基硒化物电催化剂（CuSe _y /NiSe _x /NF），具有富含 Cu _2–x Se、Cu ₃ Se ₂ 、Ni ₃ Se ₄ 和 NiSe ₂ 。该催化剂表现出出色的尿素电氧化性能，只需 1.31 V 即可实现 10 mA cm ^–2 并保持稳定性 96 小时。通过原位拉曼光谱和异位表征，发现NiOOH是在UOR过程中通过表面重构形成的，其中高价Ni是尿素有效氧化的关键位点。此外，电化学分析表明CuSe _y 具有双重作用。 XPS 和电化学测试分析表明，CuSe _y /NiSe _x /NF 内电子从 CuSe _y 转移到 NiSe _x 异质结构增强了催化剂的UOR动力学。此外，根据原位拉曼光谱研究结果，CuSe _y 的存在促进了 NiSe _x 更容易、更快速的表面重建，从而为尿素创造了额外的活性位点氧化。更重要的是，这项工作为高效UOR提供了优异的“预催化剂”，同时深入了解电催化剂结构变化背后的机制并发现其真正的活性位点。