Urea is often present in waste water but can be used in powering fuel cells and as an alternative oxidation substrate to water in an electrolyser. However, an insufficient mechanistic understanding and the lack of efficient catalysts for the urea oxidation reaction have hampered the development of such applications. Here we demonstrate that a nickel ferrocyanide (Ni₂Fe(CN)₆) catalyst supported on Ni foam can drive the urea oxidation reaction with a higher activity and better stability than those of conventional Ni-based catalysts. Our experimental and computational data suggest a urea oxidation reaction pathway different from most other Ni-based catalysts that comprise NiOOH derivatives as the catalytically active compound. Ni₂Fe(CN)₆ appears to be able to directly facilitate a two-stage reaction pathway that involves an intermediate ammonia production (on the Ni site) and its decomposition to N₂ (on the Fe site). Owing to the different rate-determining steps with more favourable thermal/kinetic energetics, Ni₂Fe(CN)₆ achieves a 100 mA cm⁻² anodic current density at a potential of 1.35 V (equal to an overpotential of 0.98 V).

尿素通常存在于废水中，但可用于为燃料电池供电并作为电解槽中水的替代氧化底物。然而，对尿素氧化反应的机理理解不足和缺乏有效的催化剂阻碍了这种应用的发展。在这里，我们证明了负载在泡沫镍上的亚铁氰化镍 (Ni ₂ Fe(CN) ₆ ) 催化剂可以驱动尿素氧化反应，比传统的镍基催化剂具有更高的活性和更好的稳定性。我们的实验和计算数据表明尿素氧化反应途径不同于大多数其他包含 NiOOH 衍生物作为催化活性化合物的镍基催化剂。镍₂铁(CN) ₆似乎能够直接促进两阶段反应途径，该途径涉及中间氨生成（在 Ni 位点）及其分解成 N ₂（在 Fe 位点）。由于具有更有利的热/动力学能量学的不同的速率确定步骤，Ni ₂ Fe(CN) ₆在1.35 V的电位（等于0.98 V的过电位）下实现了100 mA cm ^{-2的阳极电流密度。}