Highly dispersed Ni/MgO-mSiO2 catalysts with excellent activity and stability for dry reforming of methane

Highly dispersed Ni catalyst and alkaline promoters supported by mesoporous SiO2 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 CH4 and CO2 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 CO2 (CO2-TPD), and thermal gravitational analysis (TGA), the promotion effect of MgO on the Ni catalyst was systematically studied. The introduction of Mg2+ in synthesis enhanced the interaction between Ni2+ 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 CH4 but also promoted the activation of CO2 and the elimination of carbon deposits. A high and stable conversion of CH4 and CO2 were then achieved through the synergistic effect of Ni catalyst, MgO promoter, and mSiO(2) support.

Automated summary

A highly dispersed Ni catalyst supported by mesoporous SiO2 nanospheres and promoted by alkaline MgO was synthesized and used as an active and stable catalyst for dry reforming of methane (DRM). The Ni/MgO-mSiO(2) catalyst showed superior performance compared to similar catalysts in literatures, with stable CH4 and CO2 conversions around 82% and 85% during 120 hours of DRM reaction. The promotion effect of MgO on the Ni catalyst was systematically studied and found to enhance the dispersion of active centers, inhibit sintering and deactivation of Ni, and facilitate the cracking of CH4, activation of CO2, and elimination of carbon deposits.