一步法合成碳载钨酸镍催化剂的尿素电解制氢性能  

One-step synthesis of carbon-loaded nickel tungstate catalyst for hydrogen production via urea electrolysis

作　　者：张珂 郭嘉玉 周名星 赵凌 王鹭 ZHANG Ke;GUO Jiayu;ZHOU Mingxing;ZHAO Ling;WANG Lu(School of Civil Engineering,Chang′an University,Xi′an 710061,Shaanxi Province,China;Department of Chemical and Biological Engineering,The Hong Kong University of Science and Technology,Hong Kong 999077,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]香港科技大学化学及生物工程学系,中国香港999077

出　　处：《化学工程》2025年第3期1-6,共6页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(22008189);陕西省自然科学基础研究计划项目(2019JQ-587)。

摘　　要：开发高效UOR(尿素氧化反应)催化剂对强化尿素电解以实现富尿素废水绿色处理协同节能制氢至关重要。采用一步共沉淀法合成多壁碳纳米管负载的无定形钨酸镍纳米催化剂(NiWO_(4)/MWCNTs)用于尿素电解制氢,通过优化NiWO_(4)和MWCNTs的质量比实现对UOR高达1158.2 mA/mg的质量活性,是单独NiWO_(4)的5倍多;此外,碳载钨酸镍催化剂的电化学活性比表面积A_(ES)和本征催化活性也得到显著提升。进一步由峰电流I_(pa)与扫速平方根v^(1/2)呈线性关系可得NiWO_(4)/MWCNTs催化剂上的尿素电氧化过程主要受扩散控制,其高UOR活性可能归因于MWCNTs独特的空心管状结构促进了扩散。利用NiWO_(4)/MWCNTs作为阳极催化剂组装尿素电解槽,达到10、100 mA/cm^(2)电流密度所需电解电压分别为1.35、1.53 V,比水电解低170、296 mV,并且尿素电解产氢速率是水电解的9倍,同时具有超过200 h的优异尿素电解稳定性。结果表明,NiWO_(4)/MWCNTs催化剂在尿素电解节能制氢方面具备良好的应用前景。Urea electrolysis is essential for the green treatment of urea-rich wastewater synergized with energy-saving hydrogen production.It is critically dependent on the development of high-performance UOR(urea oxidation reaction)catalysts.Herein,multi-walled carbon nanotubes-loaded amorphous nickel tungstate nanocatalyst(NiWO_(4)/MWCNTs)was synthesized by one-step co-precipitation method for hydrogen production via urea electrolysis.By optimizing the mass ratio of NiWO_(4) and MWCNTs,NiWO_(4)/MWCNTs catalyst exhibits a mass activity up to 1158.2 mA/mg for UOR,which is 5 times higher than NiWO_(4).Moreover,the electrochemical active surface area A_(ES) and intrinsic catalytic activity of the carbon-loaded nickel tungstate are significantly enhanced.Furthermore,the linear relationship between anodic peak current I_(pa) and square root of scan rate v^(1/2) indicates that electrocatalytic oxidation of urea on NiWO_(4)/MWCNTs catalyst is mainly controlled by the diffusion process.The increased UOR activity of NiWO_(4)/MWCNTs could be attributed to the promotion of diffusion by the unique hollow tubular structure of MWCNTs.To evaluate the urea electrolysis performance,a urea electrolyser was assembled with NiWO_(4)/MWCNTs catalyst as the anode.Under the current densities of 10 mA/cm^(2) and 100 mA/cm^(2),the electrolysis voltages are 1.35 V and 1.53 V,respectively,which are 170 mV and 296 mV lower than that of water electrolysis.In addition,the hydrogen production rate of urea electrolysis is 9 times higher than water electrolysis and the NiWO_(4)/MWCNTs catalyst exhibits outstanding urea electrolysis stability over 200 h.These results indicate that NiWO_(4)/MWCNTs catalyst presents a good prospect for energy-saving hydrogen production via urea electrolysis.

关 键 词：钨酸镍 多壁碳纳米管 电催化氧化 尿素电解 制氢 

分 类 号：O643.36[理学—物理化学] TQ116.2[理学—化学]