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 CO₂ reduction and CH₃OH 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 CO₂ conversion to *CH₂O and CH₃OH oxidation to *CH₃O. Subsequently, an asymmetric carbon-oxygen coupling process between these two crucial intermediates produces dimethoxymethane. This work presents a CO₂ photocatalytic reduction system for multi-carbon production to meet the objectives of sustainable economic development and carbon neutrality.

目前，传统的二甲氧基甲烷合成方法对环境不友好。在这里，我们报道了一种光氧化还原催化系统，使用银和钨共改性的蓝色二氧化钛催化剂（Ag.W-BTO），在温和条件下耦合CO ₂还原和CH ₃ OH氧化生成二甲氧基甲烷。通过结合先进的表征和理论研究，对 Ag.W-BTO 结构及其电子和空穴传输进行了全面研究。引人注目的是，在没有牺牲剂的情况下，Ag.W-BTO 在 9 小时的紫外-可见光照射下实现了创纪录的光催化活性 5702.49 µmol g ^-1和 92.08% 的二甲氧基甲烷选择性。系统同位素标记实验、原位漫反射红外傅里叶变换分析和理论计算表明，Ag和W物种分别催化CO ₂转化为*CH ₂ O和CH ₃ OH氧化为*CH ₃ O。这两个关键中间体之间的不对称碳-氧偶联过程产生二甲氧基甲烷。这项工作提出了一种用于多碳生产的CO ₂光催化还原系统，以满足可持续经济发展和碳中和的目标。