Light-assisted ethanol dry reforming over NiZnOx hollow microspheres with enhanced activity and stability

Light-assisted thermocatalytic dry reforming of ethanol (EDR) utilizing the synergistic effect of photocatalysis and thermocatalysis is regarded as a promising route to convert greenhouse gas CO 2 into value-added chemicals. In this work, double-shell NiZnO x hollow microspheres (NiZnO x -M) were synthesized as light-harvesting catalyst to enhance EDR performance under mild conditions. The characterization results of UV–vis–NIR and Photoluminescence Spectroscopy (PL) indicated that the band gap energy of NiZnO x -M catalyst was narrower because of the smaller Ni nanoparticles , thereby broadening its optical response range especially in visible light. The strong absorbance of light could greatly improve the activation of ethanol/CO 2 and the gasification of carbon. With light irradiation, light could induce the transfer of photogenerated electron from semiconductor ZnO to active metal Ni, reducing the reaction energy barrier. Hence, NiZnO x -M catalyst showed superior photothermal catalytic activity along with good resistance capacity to coke accumulation and aggregation of active metal. Ethanol conversion was ca.2 times those obtained over NiZnO x -C prepared by conventional precipitation method. No obvious deactivation occurred after 100 h tests. This work provides some guidance for the design of high-performance photothermal catalyst to achieve the photo-thermal-chemical conversion of the greenhouse gases.