A Metal‐Segregation Approach to Generate CoMn Alloy for Enhanced Photothermal Conversion of Syngas to Light Olefins

As a promoter, Mn is widely used in Fischer–Tropsch synthesis (FTS) such as in the form of MnO, but few studies have focused on the effect of CoMn alloy on catalytic performance of FTS. Herein, a catalyst of CoMn alloy–loaded MnO is synthesized by a one‐step wet‐chemical method. The metallic Mn is formed through a segregation process from MnO support, which is induced by Co that is decomposed from Co‐contained precursor; then, the two metals form an alloy in the following growing process. In photothermocatalytic FTS, the optimized catalyst delivers good selectivity for light olefins (27.0% with the ratio of olefins to paraffins = 3.2); meanwhile, low CO₂selectivity (22.6%) ensures the effective use of carbon resources. Characterizations, including X‐ray photoelectron spectroscopy, high‐resolution transmission electron microscopy, and energy dispersive X‐ray mapping, reveal that the catalysts comprise CoMn alloy on MnO support. The formed CoMn alloy is the key for promoting the generation of light olefins. This study demonstrates a novel catalyst of CoMn alloy–loaded MnO for the production of light olefins via CO hydrogenation, which attains a value‐added solar‐to‐chemical energy conversion.