In recent decades, rising anthropogenic greenhouse gas emissions (mainly CO2 and CH4 ) have increased alarm due to escalating effects of global warming. The dry carbon dioxide reforming of methane (DRM) reaction is a sustainable way to utilize these notorious greenhouse gases. This paper presents a review of recent progress in the development of nickel-based catalysts for the DRM reaction. The enviable low cost and wide availability of nickel compared with noble metals is the main reason for persistent research efforts in optimizing the synthesis of nickel-based catalysts. Important catalyst features for the rational design of a coke-resistant nickel-based nanocatalyst for the DRM reaction are also discussed. In addition, several innovative developments based on salient features for the stabilization of nickel nanocatalysts through various means (which include functionalization with precursors, synthesis by plasma treatment, stabilization/confinement on mesoporous/microporous/carbon supports, and the formation of metal oxides) are highlighted. The final part of this review covers major issues and proposed improvement strategies pertaining to the rational design of nickel-based catalysts with high activity and stability for the DRM reaction.

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The effect of Na loading on the water–gas shift (WGS) activity of Ni/xNa/CeO2 (with x = 0, 0.5, 1, 2, 5, and 10 wt %) catalysts has been investigated. Ni/2Na/CeO2 exhibited the highest performance in terms of WGS activity and methane suppression. Through H2-TPR and XRD, the solubility limit of Na+ in CeO2 was found to be 2 wt %. At low loadings of Na (0.5 to 2 wt %), Na+ was incorporated into the CeO2 lattice, generating a lattice strain and activating the lattice O2, thereby increasing the reducibility of the catalyst. However, beyond the solubility limit of 2 wt %, Na deposited on the CeO2 surface, retarding the reducibility of the catalyst. XPS spectra reveal greater surface concentration of adsorbed oxygen species with the introduction of Na. This can be attributed to the generation of more oxide vacancies for oxygen adsorption due to Na substitution into the ceria lattice. By in situ DRIFTS, methanation was found to be inhibited by the interaction between Na and Ni, leading to the absence of subcarbonyl species which are responsible for this undesirable side reaction.

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