Enhancement of non-thermal plasma-catalytic CO2 reforming of CH4 using Ni/Mg–Al2O3 catalysts in a parallel plate dielectric barrier discharge reactor

CO₂ and CH₄ are converted to syngas by dry reforming of methane (DRM) reaction. This research investigated the effects of the Mg promoter on Al₂O₃-supported Ni catalysts and Mg calcination temperature on the DRM performance in a parallel plate dielectric barrier discharge reactor. The Mg promoter played a crucial role in the DRM performance, as increasing the Mg calcination temperature from 700 °C to 800 °C significantly improved the DRM performance and catalyst properties, including increased specific surface area, decreased total acidity, reduced crystallite and particle sizes, and more uniform dispersion of the Ni nanoparticles. Under these conditions, the H₂ and CO selectivity were 77.0 % and 70.7 %, the CH₄ and CO₂ conversion were 25.1 % and 20.6 %, and the energy efficiency was 8.4 %. In addition, the catalyst was associated with a lower coking rate (0.5 mg C/g_cat h), a relatively low carbon deposit of 1.5 %, and a carbon loss of 2.8 %, possibly because the weak acidity hindered the Boudouard reaction and CH₄ decomposition. However, increasing the Mg calcination temperature to 900 °C increased the total acidity and Ni particle size, decreasing H₂ and CO selectivities and increasing carbon deposits on the catalyst surface.