Lai Yuemiao, Wang Ruimin, Zeng Yi, Li Fangliang, Chen Xiao, Wang Tao, Fan Hongjun, Guo Qing
Shenzhen Key Laboratory of Energy Chemistry & Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, PR China.
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China.
JACS Au. 2024 Mar 26;4(4):1396-1404. doi: 10.1021/jacsau.3c00771. eCollection 2024 Apr 22.
Understanding the microkinetic mechanism underlying photocatalytic oxidative methane (CH) conversion is of significant importance for the successful design of efficient catalysts. Herein, CH photooxidation has been systematically investigated on oxidized rutile(R)-TiO(110) at 60 K. Under 355 nm irradiation, the C-H bond activation of CH is accomplished by the hole-trapped dangling O center rather than the hole-trapped O center via the Eley-Rideal reaction pathway, producing movable CH radicals. Subsequently, movable CH radicals encounter an O/OH species to form CHO/CHOH species, which could further dissociate into CHO under irradiation. However, the majority of the CH radical intermediate is ejected into a vacuum, which may induce radical-mediated reactions under ambient conditions. The result not only advances our knowledge about inert C-H bond activation but also provides a deep insight into the mechanism of photocatalytic CH conversion, which will be helpful for the successful design of efficient catalysts.
了解光催化氧化甲烷（CH）转化背后的微观动力学机制对于成功设计高效催化剂具有重要意义。在此，在60 K下对氧化金红石（R）-TiO(110)上的CH光氧化进行了系统研究。在355 nm光照下，CH的C-H键活化是通过空穴捕获的悬空O中心而非空穴捕获的O中心，经由埃里-里德反应途径实现的，生成可移动的CH自由基。随后，可移动的CH自由基与O/OH物种相遇形成CHO/CHOH物种，在光照下它们可进一步分解为CHO。然而，大多数CH自由基中间体被喷射到真空中，这可能会在环境条件下引发自由基介导的反应。该结果不仅推进了我们对惰性C-H键活化的认识，还为光催化CH转化的机制提供了深入见解，这将有助于成功设计高效催化剂。
