Fe, Co and Fe/Co catalysts supported on SBA-15 for Fischer-Tropsch Synthesis

Effects of the Crystalline Properties of Hollow Ceria Nanostructures on a CuO-CeO2 catalyst in CO Oxidation

The development of an efficient and economic catalyst with high catalytic performance is always challenging. In this study, we report the synthesis of hollow CeO2 nanostructures and the crystallinity control of a CeO2 layer used as a support material for a CuO-CeO2 catalyst in CO oxidation. The hollow CeO2 nanostructures were synthesized using a simple hydrothermal method. The crystallinity of the hollow CeO2 shell layer was controlled through thermal treatment at various temperatures. The crystallinity of hollow CeO2 was enhanced by increasing the calcination temperature, but both porosity and surface area decreased, showing an opposite trend to that of crystallinity. The crystallinity of hollow CeO2 significantly influenced both the characteristics and the catalytic performance of the corresponding hollow CuO-CeO2 (H-Cu-CeO2) catalysts. The degree of oxygen vacancy significantly decreased with the calcination temperature. H-Cu-CeO2 (HT), which presented the lowest CeO2 crystallinity, not only had a high degree of oxygen vacancy but also showed well-dispersed CuO species, while H-Cu-CeO2 (800), with well-developed crystallinity, showed low CuO dispersion. The H-Cu-CeO2 (HT) catalyst exhibited significantly enhanced catalytic activity and stability. In this study, we systemically analyzed the characteristics and catalyst performance of hollow CeO2 samples and the corresponding hollow CuO-CeO2 catalysts.

Production of Light Olefins via Fischer-Tropsch Process Using Iron-Based Catalysts: A Review

The production of light olefins, as the critical components in chemical industries, is possible via different technologies. The Fischer–Tropsch to olefin (FTO) process aims to convert syngas to light olefins with high selectivity over a proper catalyst, reduce methane formation, and avoid the production of excess CO2. This review describes the production of light olefins through the FTO process using both unsupported and supported iron-based catalysts. The catalytic properties and performances of both the promoted and bimetallic unsupported catalysts are reviewed. The effect of support and its physico-chemical properties on the catalyst activity are also described. The proper catalyst should have high stability to provide long-term performance without reducing the activity and selectivity towards the desired product. The good dispersion of active metals on the surface, proper porosity, optimized metal-support interaction, a high degree of reducibility, and providing a sufficient active phase for the reaction are important parameters affecting the reaction. The selection of the suitable catalyst with enhanced activity and the optimum process conditions can increase the possibility of the FTO reaction for light-olefins production. The production of light olefins via the FTO process over iron-based catalysts is a promising method, as iron is cheap, shows higher resistance to sulfur, and has a higher WGS activity which can be helpful for the feed gas with a low H2/CO ratio, and also has higher selectivity towards light olefins.