Enhanced CO2 hydrogenation to light hydrocarbons on Ni-based catalyst by DBD plasma.

The high thermal stability of CO 2 makes its conversion low in conventional thermal catalysis. Comparatively, non-equilibrium plasma technique provides an efficient way for CO 2 hydrogenation under mild reaction conditions. Introducing effective catalysts to the dielectric barrier discharge (DBD) plasma reactor may further improve CO 2 hydrogenation performance. In this way, the interaction between plasma and catalysts is important to contribute CO 2 hydrogenation performance. Considering Ni-based catalyst is active for CO 2 hydrogenation, we used three different kinds of carrier materials including CeO 2 , γ-Al 2 O 3 and ZSM-5 as supports to prepare nickel-based catalysts by incipient impregnation in this paper. The supported Ni catalysts were tested for the plasma-induced CO 2 hydrogenation to CH 4 and C 2+ hydrocarbons in the DBD-plasma reactor. It was found that the 15Ni/CeO 2 catalyst achieved the best CO 2 conversion of 85.7% and nearly 100% CH 4 selectivity at 300 °C due to its high reducibility and CO 2 chemisorption capacity. In addition, a significant synergistic effect was found between DBD plasma and catalyst. The performance of plasma-catalysis was considerably better than that of thermal catalysis plus pure plasma reaction, and the synergistic effects were enhanced with increase of reaction temperature. Moreover, the mechanism of the synergistic effect was proposed by analyzing the optical emission spectroscopy (OES) of DBD plasma, which provides a theoretical basis for further optimizing and application of plasma-catalysis for CO 2 hydrogenation reaction. [Display omitted] • CO 2 hydrogenation to CH 4 and C 2+ hydrocarbons was enhanced by plasma-catalysis. • The 15Ni/CeO 2 showed better activity due to better reducibility and CO 2 chemisorption ability. • A synergistic effect between plasma and catalyst was enhanced with increase in reaction temperature. • The synergistic mechanism between plasma and catalysts was proposed. [ABSTRACT FROM AUTHOR]