Non-thermal plasma catalytic dry reforming of methane over Ni-Co₃O₄ supported modified-titania catalysts: Effect of process conditions on syngas production

The dry reforming of methane has been studied over modified TiO₂-supported 10%Ni-5%Co₃O₄ composite catalysts using a non-thermal plasma dielectric barrier discharge fixed-bed reactor. The 10%Ni-5%Co₃O₄/modified-TiO₂ nanorods (NR) have been synthesized by hydrothermal method. Physicochemical characterizations of the composite catalysts have been conducted by X-ray diffraction (XRD), H₂ temperature-programmed reduction (H₂-TPR), CO₂ temperature-programmed desorption (CO₂-TPD), high-resolution transmission electron microscopy (HRTEM) and N₂ adsorption-desorption (BET) analysis. Incorporation of cubic-structured Co₃O₄ into Ni/TiO₂ attributes to the enhancement of basicity, reducibility and metal-support interaction. Consequently, the catalytic activity of 10%Ni-5%Co₃O₄/TiO₂ NR increases and confer CH₄ and CO₂ conversions at 86.4% and 84.9%, respectively. Meanwhile, the H₂ and CO selectivity are reported as 50.1% and 49.0% respectively. Higher syngas ratio (H₂/CO) from 0.84 to 1.01 and 26% increment in overall energy efficiency compared to plasma DRM alone have been observed. The superior plasma DRM performance is correlated to the greater basicity properties and the synergistic effect of non-thermal plasma with the 10%Ni-5%Co₃O₄/modified-TiO₂ catalyst composite.