Authors: Yuhang Gao, Jingnan Wang, Yijun Yang, Jian Wang, Chuang Zhang, Xi Wang, Jiannian Yao
Published: 2023-06-21
DOI: 10.1007/s40820-023-01127-0
Source: Full article
AbstractThe catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for electrocatalytic urea via a coordination strategy in a metal–organic frameworks: CuIII-HHTP and CuII-HHTP. CuIII-HHTP exhibits an improved urea production rate of 7.78 mmol h−1 g−1 and an enhanced Faradaic efficiency of 23.09% at − 0.6 V vs. reversible hydrogen electrode, in sharp contrast to CuII-HHTP. Isolated CuIII species with S = 0 spin ground state are demonstrated as the active center in CuIII-HHTP, different from CuII with S = 1/2 in CuII-HHTP. We further demonstrate that isolated CuIII with an empty $${d}_{{{\text{x}}^{2}\text{-y}}^{2}}^{0}$$