Selective photocatalytic aerobic oxidation of methane into carbon monoxide over Ag/AgCl@SiO2

Jianxin Zhai; Baowen Zhou; Haihong Wu; Shuaiqiang Jia; Mengen Chu; Shitao Han; Wei Xia; Mingyuan He; Buxing Han

doi:10.1039/d2sc01140a

Selective photocatalytic aerobic oxidation of methane into carbon monoxide over Ag/AgCl@SiO₂

Chem Sci. 2022 Mar 30;13(16):4616-4622. doi: 10.1039/d2sc01140a. eCollection 2022 Apr 20.

Authors

Jianxin Zhai¹, Baowen Zhou², Haihong Wu¹, Shuaiqiang Jia¹, Mengen Chu¹, Shitao Han¹, Wei Xia¹, Mingyuan He¹, Buxing Han^{1

3}

Affiliations

¹ Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University Shanghai 200062 China Mingyuanhe@126.com hhwu@chem.ecnu.edu.cn.
² Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University Shanghai 200240 China zhoubw@sjtu.edu.cn.
³ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China hanbx@iccas.ac.cn.

Abstract

Design of active catalysts for chemical utilization of methane under mild conditions is of great importance, but remains a challenging task. Here, we prepared a Ag/AgCl with SiO₂ coating (Ag/AgCl@SiO₂) photocatalyst for methane oxidation to carbon monoxide. High carbon monoxide production (2.3 μmol h^-1) and high selectivity (73%) were achieved. SiO₂ plays a key role in the superior performance by increasing the lifetime of the photogenerated charge carriers. Based on a set of semi in situ infrared spectroscopy, electron paramagnetic resonance, and electronic property characterization studies, it is revealed that CH₄ is effectively and selectively oxidized to CO by the in situ formation of singlet ¹O₂ via the key intermediate of COOH*. Further study showed that the Ag/AgCl@SiO₂ catalyst could also drive valuable conversion using real sunlight under ambient conditions. As far we know, this is the first work on the application of SiO₂ modified Ag/AgCl in the methane oxidation reaction.