Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105, PR China.
Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105, PR China.
J Colloid Interface Sci. 2023 Jan;629(Pt A):33-43. doi: 10.1016/j.jcis.2022.08.095. Epub 2022 Aug 18.
Electrochemical urea oxidation reaction (UOR) is urgently in demand for diverse energy conversion and storage device coupled with pollution treatment because of its favorable thermodynamic potential (0.37 V vs RHE) and wide distribution nature of urea, but simultaneously gravely limited by the sluggish reaction dynamics and poisoning of catalyst. Herein, dual-phased NiSe/NiSe coupling with N doped carbon (NiSe/NiSe@NC-2) in situ is prepared by a solvothermal-selenization pathway. Benefiting from the collective promotion of the dual-phased composition and the NC support, NiSe/NiSe@NC provides abundant active sites, enhanced electrical conductivity. It delivers a current density of 252 mA cm at 1.6 V vs RHE with a small Tafel slop of 64.4 mV dec and gets a lower reaction barrier. Moreover, it requires a cell voltage of 1.46 V to approach 50 mA cm, about 250 mV less than that of water electrolysis, confirming the less energy consumption. Notably, the N doped carbon protects NiSe/NiSe nanocrystals from aggregation leading to a faster CO desorption from Ni sites, which endow the NiSe/NiSe@NC-2 a much better working stability. The direct urea hydrogen peroxide fuel cell (DUHPFC) achieves a maximum power density of 9.09 mW cm at 20 °C. This work extends highly efficient dual-phased structure loading in NC catalysts system for urea-assisted energy conversion.
电化学尿素氧化反应（UOR）由于其有利的热力学势（相对于 RHE 为 0.37 V）和尿素广泛的分布性质，与各种能量转换和存储装置以及污染处理相结合，因此迫切需要，但同时严重受到反应动力学缓慢和催化剂中毒的限制。在此，通过溶剂热-硒化途径原位制备了双相 NiSe/NiSe 与 N 掺杂碳（NiSe/NiSe@NC-2）的复合材料。得益于双相组成和 NC 载体的协同促进作用，NiSe/NiSe@NC 提供了丰富的活性位点，增强了导电性。它在 1.6 V 时的电流密度为 252 mA cm，Tafel 斜率为 64.4 mV dec，反应势垒较低。此外，它需要 1.46 V 的电池电压才能达到 50 mA cm，比水电解低约 250 mV，这证实了其较低的能耗。值得注意的是，N 掺杂碳保护 NiSe/NiSe 纳米晶不聚集，从而使 Ni 位上的 CO 更快脱附，这使 NiSe/NiSe@NC-2 具有更好的工作稳定性。直接尿素过氧化氢燃料电池（DUHPFC）在 20°C 时实现了 9.09 mW cm 的最大功率密度。这项工作扩展了高效双相结构在 NC 催化剂系统中负载用于尿素辅助能量转换的应用。
