Oleylamine‐Assisted Construction of Bi‐Bi 2 O 2 CO 3 Heterojunction With a Self‐Release‐Replenish
Jiarui Zhang, Haidong Shen, Zhanwei Chen, Peng Zhao, ShiLong Song, Hao Jiang, Yanjun Wen, Shaowei Yang, Qiuyu Zhang, Hepeng ZhangABSTRACT
Bismuth‐based catalysts for the electrochemical CO 2 reduction (CO 2 RR) to formate have been extensively developed, yet the limited mass transport of gaseous CO 2 remains a sspersistent challenge. Herein, we report a novel Bi‐Bi 2 O 2 CO 3 heterojunction electrocatalyst (Bi‐BOC‐OLA) constructed via an oleylamine‐assisted strategy and disclose a new self‐release‐replenishing Mars‐van Krevelen‐type mechanism that alleviates this constraint. Oleylamine‐induced expansion of [Bi 2 O 2 ] 2+ layers enables the Bi 2 O 2 CO 3 lattice in Bi‐BOC‐OLA to function as an in situ carbon reservoir that continuously supplies carbon–oxygen intermediates to active Bi centers. External CO 2 replenishes lattice vacancies, creating an energy‐efficient cycle that reduces reliance on gaseous CO 2 transport. Consequently, Bi‐BOC‐OLA achieves a formate Faradaic efficiency of 97%, a record partial current density of −1.4 A cm −2 and stable operation for 160 h at −400 mA cm −2 . This work reveals how dynamic lattice participation in Bi‐Bi 2 O 2 CO 3 heterojunctions enables high‐rate CO 2 ‐to‐formate conversion and provides a new mechanistic basis for the design of Bi‐based CO 2 RR catalysts.