Cobalt@Silica Core‐Shell Catalysts for Hydrogenation of CO/CO2 Mixtures to Methane

Abstract

AbstractCOx hydrogenation reactions for hydrocarbon synthesis, such as methane, are becoming more and more important in terms of the energy transition. The formation of the byproduct water leads to a hydrothermal environment, which necessitates stable catalyst materials under harsh reaction conditions. Therefore, novel nanostructured core‐shell catalysts are part of scientific discussion, since these materials offer an exceptional resistance against thermal sintering. Here we report on a core‐shell catalyst ‐ Co@mSiO2 ‐ for the hydrogenation of CO/CO2 mixtures towards methane. CO methanation experiments reveal a rapid temperature‐depended deactivation for temperatures above 350 °C caused by coking and possible blocking of the pores. In comparison to a Co/mSiO2 reference catalyst with the same Co particle size a significantly higher methane selectivity was found for CO2 hydrogenation, which we attribute to the confinement effect of the core‐shell structure and therefore a higher probability of CO readsorption. Finally, the simultaneous CO/CO2 co‐methanation experiments show a high flexibility of the catalyst materials on different gas feed compositions.