华中科技大学翟天佑团队报道了耦合界面原位相分离促进宽电位窗口下CO2电还原生成甲酸盐。相关研究成果发表在2021年8月13日出版的《德国应用化学》。

双金属硫化物有望在较宽的电位窗口内实现有效的CO₂电还原生成甲酸盐，但在反应条件下会发生原位结构演变。因此，阐明其结构演化过程、真正的活性中心和催化机理具有重要意义。

该文中，以Cu₂SnS₃为例，研究人员揭示了Cu₂SnS₃发生自适应相分离以形成稳定相SnO^₂@CuS及SnO₂@Cu₂O电化学过程中的异质结。理论计算表明，强耦合界面作为真实活性中心驱动电子从Sn⁴⁺向Cu⁺自流，从而促进离域Sn位结合HCOO*和H*。Cu₂SnS₃纳米片在-0.6 V至-1.1 V的宽电位范围内实现了83.4%以上的甲酸选择性生产。

研究结果为深入了解CO₂电还原条件下三元硫化物的结构演变过程和性能增强起源提供了依据。

附：英文原文

Title: In Situ Phase Separation into Coupled Interfaces for Promoting CO2 Electroreduction to Formate over a Wide Potential Window

Author: Wenbin Wang, Zhitong Wang, Ruoou Yang, Junyuan Duan, Youwen Liu, Anmin Nie, Huiqiao Li, Bao Yu Xia, Tianyou Zhai

Issue&Volume: 2021-08-13

Abstract: Bimetallic sulfides are expected to realize efficient CO2 electroreduction into formate over a wide potential window, however, will undergo in situ structural evolution under the reaction conditions. Therefore, clarifying the structural evolution process, the real active site and the catalytic mechanism appear significance. Here, taking Cu2SnS3 as an example, we unveiled that Cu2SnS3 occurred self-adapted phase separation toward forming the stable SnO2@CuS and SnO2@Cu2O heterojunction during the electrochemical process. Theoretical calculations illustrated that the strongly coupled interfaces as real active sites driven the electron self-flow from Sn4+ to Cu+, thereby promoting the delocalized Sn sites to combine HCOO* with H*. Cu2SnS3 nanosheets achieve over 83.4% formate selectivity in a wide potential range from -0.6 V to -1.1 V. Our findings provide insight into the structural evolution process and performance-enhanced origin of ternary sulfides under the CO2 electroreduction.

DOI: 10.1002/anie.202110000

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202110000