CO2 conversion via dry reforming of methane on a core-shell Ru@SiO2 catalyst

Abstract

Dry reforming of methane (DRM) over metal catalysts represents an economically feasible method to convert the greenhouse gas CO2 into valuable chemical products. Owing to the strong stability of both CH4 and CO2 molecules, the reaction usually occurs at very high temperatures, so that the key problem of the reaction is catalysts agglomeration. In this study, we developed a novel core-shell Ru@SiO2 catalyst by encapsulating Ru nanoparticles in SiO2 shells through a reversed-phase microemulsion method. The as-produced core-shell Ru@SiO2 catalyst effectively enhanced the thermal stability of the Ru nanoparticles against gathering at high temperatures, owing to the confinement effect of the SiO2 shells on the Ru nanoparticles and a sturdy support-metal interaction. Thus, the developed catalyst exhibited a longer lifetime than those of both the unsupported Ru and traditional Ru/SiO2 catalysts. More importantly, the ultrafine Ru nanoparticles provided both abundant active sites and high instinct activity. Further more, the ultrafine Ru nanoparticles also inhibited carbon generation, thereby preventing catalyst deactivation. To the best of our knowledge, this as-produced core-shell Ru@SiO2 is one of the best DRM catalysts at high space velocities reported to date.