Urea oxidation reaction (UOR) is considered an ideal water splitting reaction with the potential to replace oxygen evolution reaction (OER), as it lowers the anodic potential and utilizes urea as a renewable and abundant resource. However, creating stable, effective bifunctional catalysts is still challenging. In this work, we report a novel bifunctional catalyst of core-shell structure Ni-500 Nano-particle. The carbon coating not only offers numerous active sites and facilitates rapid charge transfer but also shields the nickel core from corrosion. Moreover, By replenishing the urea concentration, the current density can be recovered and sustained for 50 h with only an 8 % decrease. It is significantly less than pure water electrolysis that the urea-assisted water electrolyzer with Ni-500 as both cathode and anode achieves cell-voltage of 1.55 V at 100 mA cm. This work demonstrates the potential of Ni-500 as a inexpensive and effective catalyst for urea-based hydrogen production, and offers new perspectives into the design and optimization for core-shell structure electrocatalyst.

中文翻译：

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封装在碳壳中的镍金属颗粒作为尿素辅助制氢的高效双功能电催化剂


尿素氧化反应（UOR）被认为是一种理想的水分解反应，具有取代析氧反应（OER）的潜力，因为它降低了阳极电位并利用尿素作为可再生和丰富的资源。然而，制造稳定、有效的双功能催化剂仍然具有挑战性。在这项工作中，我们报道了一种新型的核壳结构Ni-500纳米颗粒双功能催化剂。碳涂层不仅提供大量活性位点并促进快速电荷转移，而且还可以保护镍芯免受腐蚀。而且，通过补充尿素浓度，电流密度可以恢复并维持50h，仅下降8%。以Ni-500为阴极和阳极的尿素辅助水电解槽在100mAcm下达到1.55V的槽电压，明显低于纯水电解。这项工作展示了Ni-500作为一种廉价且有效的尿素制氢催化剂的潜力，并为核壳结构电催化剂的设计和优化提供了新的视角。