Abstract:
The green and sustainable electrocatalytic conversion of nitrogen-containing compounds to ammonia is currently in high demand in order to replace the eco-unfriendly Haber-Bosch process. Model catalysts for the nitrate reduction reaction were obtained by electrodeposition of metal Co, Fe, and bimetallic Fe/Co nanoparticles from aqueous solutions onto a graphite substrate. The samples were characterized by the following methods: SEM, XRD, XPS, UV-vis spectroscopy, cyclic (and linear) voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. In addition, the determination of the electrochemically active surface was also performed for all electrocatalysts. The best electrocatalyst was a sample containing Fe-nanoparticles on the layer of Co-nanoparticles, which showed a Faradaic efficiency of 58.2% (E = -0.785 V vs. RHE) at an ammonia yield rate of 14.6 μmol h-1 cm-2 (at ambient condition). An opinion was expressed to elucidate the mechanism of coordinated electrocatalytic action of a bimetallic electrocatalyst. This work can serve primarily as a starting point for future investigations on electrocatalytic conversion reactions to ammonia using model catalysts of the proposed type.
摘要:
目前,绿色和可持续的含氮化合物电催化转化为氨的需求很高,以取代对生态不友好的Haber-Bosch工艺。通过电沉积金属Co获得硝酸盐还原反应的模型催化剂,Fe,和双金属Fe/Co纳米颗粒从水溶液到石墨基底上。样品通过以下方法进行表征:SEM,XRD,XPS,紫外-可见光谱,循环(和线性)伏安法,计时电流法,和电化学阻抗谱。此外,还对所有电催化剂进行电化学活性表面的测定。最好的电催化剂是在Co纳米颗粒层上含有Fe纳米颗粒的样品,其显示的法拉第效率为58.2%(E=-0.785Vvs.RHE)的氨产率为14.6μmolh-1cm-2(在环境条件下)。有人表示要阐明双金属电催化剂的协同电催化作用机理。这项工作可以主要用作未来研究使用所提出类型的模型催化剂将电催化转化为氨的研究的起点。