Abstract:
The electrochemical nitrate reduction reaction (NO3RR) is considered a sustainable technology to convert the nitrate pollutants to ammonia. However, developing highly efficient electrocatalysts is necessary and challenging given the slow kinetics of the NO3RR with an eight-electron transfer process. Here, a Cu1.5Mn1.5O4 (CMO)/CeO2 heterostructure with rich interfaces is designed and fabricated through an electrospinning and postprocessing technique. Benefiting from the strong coupling between CMO and CeO2, the optimized CMO/CeO2-2 catalyst presents excellent NO3RR performance, with NH3 Faraday efficiency (FE) up to 93.07 ± 1.45% at -0.481 V vs reversible hydrogen electrode (RHE) and NH3 yield rate up to 48.06 ± 1.32 mg cm-2 h-1 at -0.681 V vs RHE. Theoretical calculations demonstrate that the integration of CeO2 with CMO modulates the adsorption/desorption process of the reactants and intermediates, showing a reduced energy barrier in the rate determination step of NO* to N* and achieving an outstanding NO3RR performance.
摘要:
电化学硝酸盐还原反应(NO3RR)被认为是将硝酸盐污染物转化为氨的可持续技术。然而,鉴于具有八电子转移过程的NO3RR的缓慢动力学,开发高效的电催化剂是必要且具有挑战性的。这里,通过静电纺丝和后处理技术,设计并制造了具有丰富界面的Cu1.5Mn1.5O4(CMO)/CeO2异质结构。得益于CMO与CeO2的强耦合,优化后的CMO/CeO2-2催化剂表现出优异的NO3RR性能,在-0.481V与可逆氢电极(RHE)时,NH3法拉第效率(FE)高达93.07±1.45%,在-0.681V与RHE时,NH3产率高达48.06±1.32mgcm-2h-1。理论计算表明,CeO2与CMO的集成调节了反应物和中间体的吸附/解吸过程。在NO*至N*的速率确定步骤中显示出降低的能量势垒,并实现了出色的NO3RR性能。