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

Abstract

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.

Recent Advances in Photothermal COxConversion

“…Photoexcited electrons/holes or the hot carriers play an essential role in initiating the photothermal co‐catalysis process. [ 41 ] Ozin's group prepared In 2 O 3− x (OH) y nanostructure for the photothermal RWGS reaction. [ 42 ] The generation rate of CO reached 153 μmol g cat −1 h −1 under the light illumination (1000 W m −2 ), which was 4.3 times higher than in the thermal condition.…”

Photothermal Chemistry Based on Solar Energy: From Synergistic Effects to Practical Applications

“…We have summarized a number of representative PTC works involving different fields, as shown in Table 1 . [ 33,36,38‐47,49‐57,61‐68,70‐73,75‐81,83,85,87‐89,94,111‐113,115,117,118,120,121,123‐168 ] The PTC works are categorized into three major fields, solar fuel production, chemical synthesis, and environmental remediation, and the catalysts and energy sources used in the studies, along with the reaction temperatures and reaction results are collected. Besides, the datasets of the temperatures and the reaction results have been extracted and plotted for better visibility, as shown in Figure .…”

Improvement of CO2 Photoreduction Efficiency by Process Intensification

“…Li et al [44] investigated the photo-thermocatalytic performance of syngas to olefins with a Mn-based catalyst. The reaction temperature was selected to be 250 • C. A good selectivity of 27.0% for light olefins and a ratio of olefins to paraffins equal to 3:2 were obtained.…”

“…Reactant pressure is relative to the concentration of a reactant. Rossetti et al [44] noticed that CO 2 solubility is severely limited in liquid water. The relatively high temperature, which favors the reaction kinetics, definitely caused a very poor productivity in the liquid phase.…”