Low-temperature CO2 reforming of methane on Zr-promoted Ni/SiO2 catalyst

• The Ni species enhanced the dispersion of the Zr species on the catalyst's surface.
• CO2 → COads + Oads occurred at low temperatures on Ni–Zr/SiO2 catalyst.
• Different relative proportions of carbonates were formed from CO2.
• Activation of C–H bond in CH4 at a lower temperature on Ni–Zr/SiO2 catalyst
• The synergetic effect of the Ni and Zr facilitated the DRM at low temperatures.

Ni–Zr/SiO2 catalyst was prepared using the impregnation method and was employed for the dry reforming of methane. The Ni species ensured a superior dispersion of the Zr species, promoting the formation of low temperature active center for the target reaction, while the introduction of promoter Zr changed the nature of the active center. At high temperature, the Ea values corresponding to CH4 and CO2 on Ni–Zr/SiO2 catalyst were much lower than those on Ni/SiO2 catalyst. In addition to facilitate the activation of the C–H bond in CH4, the Zr promoter on Ni–Zr/SiO2 catalyst also facilitated the formation of COads and Oads species at low temperatures, and accelerated the formation–decomposition of intermediate formates. These factors including the synergetic effect of Ni and Zr species led to the enhancement of the activation of both CH4 and CO2 at low temperatures, with 2.0% initial conversion of both CH4 and CO2 (at 1 h) achieved at 400 °C.