Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Provincial Engineering Laboratory for New-Energy Vehicle Battery Energy-Storage Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, P. R. China.
Small. 2023 Jul;19(28):e2300959. doi: 10.1002/smll.202300959. Epub 2023 Mar 27.
Coupling urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) is promising for energy-efficient hydrogen production. However, developing cheap and highly active bifunctional electrocatalysts for overall urea electrolysis remains challenging. In this work, a metastable Cu Ni alloy is synthesized by a one-step electrodeposition method. It only requires the potentials of 1.33 and -28 mV to obtain the current density of ±10 mA cm for UOR and HER, respectively. The metastable alloy is considered to be the main reason causing the above excellent performances. In the alkaline medium, the as-prepared Cu Ni alloy exhibits good stability for HER; and conversely, NiOOH species can be rapidly formed during the UOR due to the phase segregation of Cu Ni alloy. In particular, for the energy-saving hydrogen generation system coupled with HER and UOR, only 1.38 V of voltage is needed at 10 mA cm ; and at 100 mA cm , the voltage decreases by ≈305 mV compared with that of the routine water electrolysis system (HER || OER). Compared with some catalysts reported recently, the Cu Ni catalyst owns superior electrocatalytic activity and durability. Furthermore, this work provides a simple, mild, and rapid method for designing highly active bifunctional electrocatalysts toward urea-supporting overall water splitting.
耦合尿素氧化反应 (UOR) 和析氢反应 (HER) 有望实现高效节能的制氢。然而，开发用于全尿素电解的廉价且高活性双功能电催化剂仍然具有挑战性。在这项工作中，通过一步电沉积方法合成了一种亚稳 Cu-Ni 合金。它只需要 1.33 和 -28 mV 的电势即可分别获得 UOR 和 HER 的±10 mA cm 的电流密度。亚稳合金被认为是导致上述优异性能的主要原因。在碱性介质中，所制备的 Cu-Ni 合金在 HER 中表现出良好的稳定性；相反，由于 Cu-Ni 合金的相分离，在 UOR 过程中可以迅速形成 NiOOH 物种。特别是对于与 HER 和 UOR 耦合的节能制氢系统，在 10 mA cm 时仅需 1.38 V 的电压；在 100 mA cm 时，与常规水电解系统 (HER || OER) 相比，电压降低了 ≈305 mV。与最近报道的一些催化剂相比，Cu-Ni 催化剂具有更高的电催化活性和耐久性。此外，这项工作为设计用于尿素支撑全水分解的高活性双功能电催化剂提供了一种简单、温和、快速的方法。
