Shangguan Wenchao, Liu Qing, Wang Ying, Sun Ning, Liu Yu, Zhao Rui, Li Yingxuan, Wang Chuanyi, Zhao Jincai
School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
Nat Commun. 2022 Jul 6;13(1):3894. doi: 10.1038/s41467-022-31474-2.
Achieving CO reduction with HO on metal photocatalysts and understanding the corresponding mechanisms at the molecular level are challenging. Herein, we report that quantum-sized Au nanoparticles can photocatalytically reduce CO to CO with the help of HO by electron-hole pairs mainly originating from interband transitions. Notably, the Au photocatalyst shows a CO production rate of 4.73 mmol g h (~100% selectivity), ~2.5 times the rate during CO reduction with H under the same experimental conditions, under low-intensity irradiation at 420 nm. Theoretical and experimental studies reveal that the increased activity is induced by surface Au-O species formed from HO decomposition, which synchronously optimizes the rate-determining steps in the CO reduction and HO oxidation reactions, lowers the energy barriers for the *CO desorption and *OOH formation, and facilitates CO and O production. Our findings provide an in-depth mechanistic understanding for designing active metal photocatalysts for efficient CO reduction with HO.
在金属光催化剂上利用羟基自由基（HO）实现一氧化碳（CO）还原并在分子水平上理解相应机制具有挑战性。在此，我们报告量子尺寸的金纳米颗粒可以借助主要源于带间跃迁的电子 - 空穴对，在HO的帮助下将CO光催化还原为CO。值得注意的是，在420nm的低强度照射下，金光催化剂显示出4.73 mmol g h的CO生成速率（~100%选择性），在相同实验条件下，约为用氢气还原CO时速率的2.5倍。理论和实验研究表明，活性的提高是由HO分解形成的表面Au - O物种诱导的，其同步优化了CO还原和HO氧化反应中的速率决定步骤，降低了CO脱附和OOH形成的能量障碍，并促进了CO和O的生成。我们的研究结果为设计用于高效利用HO还原CO的活性金属光催化剂提供了深入的机理理解。
