Coupling photocatalytic CO2 reduction and CH3OH oxidation for selective dimethoxymethane production
Yixuan Wang, Yang Liu, Lingling Wang, P. Silambarasan, Hongdan Wang, Hyun Ko, Chung‐Li Dong, Panpan Zhang, Shuaijun Wang, Ta Thi Thuy Nga, Young Dok Kim, Yujing Ji, Shufang Zhao, Ji‐Hee Kim, D. S. Yee, Yosep Hwang, Jinqiang Zhang, Min Gyu Kim, Hyoyoung Lee
Abstract
Abstract Currently, conventional dimethoxymethane synthesis methods are environmentally unfriendly. Here, we report a photo-redox catalysis system to generate dimethoxymethane using a silver and tungsten co-modified blue titanium dioxide catalyst (Ag.W-BTO) by coupling CO 2 reduction and CH 3 OH oxidation under mild conditions. The Ag.W-BTO structure and its electron and hole transfer are comprehensively investigated by combining advanced characterizations and theoretical studies. Strikingly, Ag.W-BTO achieve a record photocatalytic activity of 5702.49 µmol g −1 with 92.08% dimethoxymethane selectivity in 9 h of ultraviolet-visible irradiation without sacrificial agents. Systematic isotope labeling experiments, in-situ diffuse reflectance infrared Fourier-transform analysis, and theoretical calculations reveal that the Ag and W species respectively catalyze CO 2 conversion to *CH 2 O and CH 3 OH oxidation to *CH 3 O. Subsequently, an asymmetric carbon-oxygen coupling process between these two crucial intermediates produces dimethoxymethane. This work presents a CO 2 photocatalytic reduction system for multi-carbon production to meet the objectives of sustainable economic development and carbon neutrality.