Activated carbon supported nickel catalyst for selective CO2 hydrogenation to synthetic methane under contactless induction heating

Abstract

The use of CO2 methanation in the power-to-gas (PtG) technology chains has received increasing attention in recent years for clean energy and sustainable development. In this work, macroscopic mesoporous nickel catalyst was prepared and evaluated for selective CO2 hydrogenation to CH4 using commercial activated carbon (AC) pellets. Catalyst samples were fully characterized by liquid N2 adsorption-desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), scanning and transmission electron microscopy (SEM/TEM). Catalytic performances were investigated under various reaction conditions with both direct induction heating (IH) and conventional indirect Joule heating (JH) modes. Results indicated that by simple thermal treatment, the surface and textural properties of the macroscopic carbon support could be greatly modified by improving the dispersion of metal sites and thus the catalytic performance. The advantages of IH combined with the inherent high thermal and electrical conductivity of the prepared materials could effectively avoid the temperature runaway and enhance the CO2 activation at relatively low reaction temperature. By comparison to the classical indirect JH mode, the resulting macroscopic nickel catalysts showed improving catalytic performances for CO2 methanation under IH mode. The efficient heat management under direct IH mode also prevented coke formation on the catalyst surface which contributes to its high stability as a function of time-on-stream.