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 CO2 selectivity (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.

Automated summary

This study successfully synthesized a novel catalyst of CoMn alloy-loaded MnO using a one-step wet-chemical method, which exhibited good selectivity for light olefins in photothermocatalytic FTS, along with low CO2 selectivity for effective use of carbon resources.