Jiang Xun-Heng, Zhang Long-Shuai, Liu Hai-Yan, Wu Dai-She, Wu Fei-Yao, Tian Lei, Liu Ling-Ling, Zou Jian-Ping, Luo Sheng-Lian, Chen Bing-Bing
Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, Jiangxi, 330063, P. R. China.
Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, School of Resources Environmental and Chemical Engineering, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
Angew Chem Int Ed Engl. 2020 Dec 14;59(51):23112-23116. doi: 10.1002/anie.202011495. Epub 2020 Oct 13.
Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag-N C /CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag-N C configuration have been identified by aberration-correction high-angle-annular-dark-field scanning transmission electron microscopy (AC-HAADF-STEM) and extended X-ray absorption. Experiments and DFT calculations further verify that Ag-N C can reduce the H evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag-N C /CN catalyst exhibits much better H evolution activity than the N-coordinated Ag single atom in CN (Ag-N /CN), and is even superior to the Pt nanoparticle-loaded CN (Pt /CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.
具有最大化金属原子效率的单原子催化剂（SACs）引发了极大关注。然而，获得具有高金属负载量、高催化活性和良好稳定性的SACs具有挑战性。在此，我们展示了一种新策略，用于在具有独特配位的氮化碳（Ag-N C /CN）催化剂中开发高活性和稳定的Ag单原子。通过像差校正高角度环形暗场扫描透射电子显微镜（AC-HAADF-STEM）和扩展X射线吸收确定了Ag原子分散和Ag-N C构型。实验和DFT计算进一步证实，Ag-N C可以降低析氢势垒，扩大光吸收范围，并改善CN的电荷转移。结果，Ag-N C /CN催化剂表现出比CN中N配位的Ag单原子（Ag-N /CN）更好的析氢活性，甚至优于负载Pt纳米颗粒的CN（Pt /CN）。这项工作为设计和合成具有新颖构型、优异催化活性和耐久性的SACs提供了新思路。
