Highly dispersed Ni/MgO-mSiO 2 catalysts with excellent activity and stability for dry reforming of methane

Highly dispersed Ni catalyst and alkaline promoters supported by mesoporous SiO 2 nanospheres were synthesized and applied as an active and stable catalyst for dry reforming of methane (DRM). The as-prepared Ni/MgO-mSiO 2 catalyst showed stable conversions of CH 4 and CO 2 around 82% and 85% in 120 h of DRM reaction, which was superior in performance compared to similar catalysts in literatures. Based on the transmission electron microscope (TEM) images, energy-dispersive spectroscopy (EDS), CO-pulse adsorption, temperature programmed reduction of the oxidized catalysts by hydrogen (H 2 -TPR), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of CO 2 (CO 2 -TPD), and thermal gravitational analysis (TGA), the promotion effect of MgO on the Ni catalyst was systematically studied. The introduction of Mg 2+ in synthesis enhanced the interaction between Ni 2+ and mSiO 2 , which led to a high dispersion of active centers and a strong “metal-support” interactions to inhibit the sintering and deactivation of Ni at reaction temperatures. On the other hand, Ni and MgO nanoparticles formed adjacently on mSiO 2 , where the “Ni-MgO” interface not only improved the Ni 0 distribution and promoted the cracking of CH 4 but also promoted the activation of CO 2 and the elimination of carbon deposits. A high and stable conversion of CH 4 and CO 2 were then achieved through the synergistic effect of Ni catalyst, MgO promoter, and mSiO 2 support.