Non-thermal plasma-enhanced dry reforming of methane and CO2 over Ce-promoted Ni/C catalysts

Abstract A series of Ce-promoted nickel supported activated carbon (NiCexC) catalysts with different molar contents of Ce (0, 0.5 %, 1 %, 3 % and 5 %) were synthesized via a wetness co-impregnation method. Catalytic activity of CO2 dry reforming of methane (DRM) was evaluated in a non-thermal plasma (NTP)-catalytic reactor. Experimental results showed that the introduction of CeO2 could promote the NTP-catalytic DRM reaction. Specifically, NiCe1C catalyst was regarded as the best one due to its excellent conversion of CO2 (53.7 %) and CH4 (55.6 %), as well as a prominent selectivity of H2 (50.0 %) and CO (53.2 %). Moreover, it was also found that NiCe1C could achieve the highest energy efficiency (0.59 mmol kJ−1) compared with NiCe0C (0.52 mmol kJ−1). A strong dual-metals interaction between Ni and CeO2 was found to inhibit the growth of Ni particle, and improve the dispersion of Ni nanoparticles (NPs), thereby the activation energy of CH4 was reduced due to the size effect. The addition of CeO2 created more basic sites with stronger basicity of the catalyst, which was beneficial to increase the adsorption capacity of the reactants, especially the acidic gas CO2. Thus, the conversion of CO2 and CH4 were further improved. Besides, the formation of coke deposition and the participation of carbon support in the reaction could be avoided by controlling CH4/CO2 ratio in the feed gases.