Tatarchuk Stephen W, Choueiri Rachelle M, MacKay Alexander J, Johnston Shayne J, Cooper William M, Snyder Kayla S, Medvedev Jury J, Klinkova Anna, Chen Leanne D
Electrochemical Technology Centre, Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Chemphyschem. 2024 Apr 16;25(8):e202300889. doi: 10.1002/cphc.202300889. Epub 2024 Mar 6.
Developing electrocatalysts for urea oxidation reaction (UOR) works toward sustainably treating urea-enriched water. Without a clear understanding of how UOR products form, advancing catalyst performance is currently hindered. This work examines the thermodynamics of UOR pathways to produce N, NO , and NO on a (0001) β-Ni(OH) surface using density functional theory with the computational hydrogen electrode model. Our calculations show support for two major experimental observations: (1) N favours an intramolecular mechanism, and (2) NO /NO are formed in a 1 : 1 ratio with OCN. In addition, we found that selectivity between N and NO /NO on our model surface appears to be controlled by two key factors, the atom that binds the surface intermediates to the surface and how they are deprotonated. These UOR pathways were also examined with a Cu dopant, revealing that an experimentally observed increased N selectivity may originate from increasing the limiting potential required to form NO . This work builds towards developing a more complete atomic understanding of UOR at the surface of NiOH electrocatalysts.
开发用于尿素氧化反应（UOR）的电催化剂有助于可持续地处理富含尿素的水。由于对UOR产物的形成方式缺乏清晰的了解，目前提高催化剂性能受到阻碍。这项工作使用密度泛函理论和计算氢电极模型，研究了在（0001）β-Ni(OH)表面上产生N、NO和NO的UOR途径的热力学。我们的计算结果支持了两个主要的实验观察结果：（1）N倾向于分子内机制，（2）NO/NO与OCN以1:1的比例形成。此外，我们发现模型表面上N与NO/NO之间的选择性似乎受两个关键因素控制，即将表面中间体与表面结合的原子以及它们如何去质子化。还使用铜掺杂剂研究了这些UOR途径，结果表明实验观察到的N选择性增加可能源于形成NO所需的极限电位增加。这项工作朝着对NiOH电催化剂表面的UOR形成更完整的原子理解方向发展。
