Self-Assembled Controllable Cu-Based Perovskite/Calcium Oxide Hybrids with Strong Interfacial Interactions for Enhanced CH<sub>4</sub> Electrosynthesis
Yu Zhang, Yunze Xu, Zitao Chen, Zhenbao Zhang, Xiangjian Liu, Zhen Xue, Xuezeng Tian, Xuedong Bai, Xue Wang, Minghua Huang, Jiawei Zhu, Heqing Jiang, Yongfa Zhu
Abstract
Cu-based perovskite oxide catalysts show promise for CO 2 electromethanation, but suffer from unsatisfactory CH 4 selectivity and poor stability. Here, we report self-assembled, controllable Cu-based perovskite/calcium oxide hybrids with strongly interacting interfaces for high-performance CH 4 electrosynthesis. As proof-of-concept catalysts, the La 2 CuO 4 /(CaO) x ( x from 0.2 to 1.2) series has tunable CaO phase concentrations and thus controllable interface sizes. The La 2 CuO 4 and CaO components are intimately connected at the interface, leading to strong interfacial interactions mainly manifested by marked electron transfer from Ca 2+ to Cu 2+ . In CH 4 electrosynthesis, their activity and selectivity show a volcano-type dependence on the CaO phase concentrations and are positively correlated with the interface sizes. Among them, the La 2 CuO 4 /(CaO) 0.8 delivers the optimal activity and selectivity for CH 4, together with good stability, much better than those of a physical-mixture counterpart and most reported Cu-based perovskite oxides. Moreover, La 2 CuO 4 /(CaO) 0.8 stands out as one of the most effective Cu-based catalysts for CH 4 electrosynthesis, achieving a high CH 4 selectivity of 77.6% at 300 mA cm –2 . Our experiments and theoretical calculations highlight the significant role of self-assembly-induced strong interfacial interactions in promoting *CO adsorption/hydrogenation, intensifying resistance to structural degradation, and consequently underpinning the achievement of such optimized performance.