Cation‐Radius‐Controlled Sn−O Bond Length Boosting CO<sub>2</sub> Electroreduction over Sn‐Based Perovskite Oxides
Mingfa Chen, Kuan Chang, Yu Zhang, Zhenbao Zhang, Yuming Dong, Xiaoyu Qiu, Heqing Jiang, Yongfa Zhu, Jiawei Zhu
Abstract
Abstract Despite the intriguing potential shown by Sn‐based perovskite oxides in CO 2 electroreduction (CO 2 RR), the rational optimization of their CO 2 RR properties is still lacking. Here we report an effective strategy to promote CO 2 ‐to‐HCOOH conversion of Sn‐based perovskite oxides by A‐site‐radius‐controlled Sn−O bond lengths. For the proof‐of‐concept examples of Ba 1−x Sr x SnO 3 , as the A‐site cation average radii decrease from 1.61 to 1.44 Å, their Sn−O bonds are precisely shortened from 2.06 to 2.02 Å. Our CO 2 RR measurements show that the activity and selectivity of these samples for HCOOH production exhibit volcano‐type trends with the Sn−O bond lengths. Among these samples, the Ba 0.5 Sr 0.5 SnO 3 features the optimal activity (753.6 mA ⋅ cm −2 ) and selectivity (90.9 %) for HCOOH, better than those of the reported Sn‐based oxides. Such optimized CO 2 RR properties could be attributed to favorable merits conferred by the precisely controlled Sn−O bond lengths, e.g., the regulated band center, modulated adsorption/activation of intermediates, and reduced energy barrier for *OCHO formation. This work brings a new avenue for rational design of advanced Sn‐based perovskite oxides toward CO 2 RR.