Plasma-catalytic reforming of CO₂-CH₄ over nickel-based catalysts: Catalyst design, plasma activation, and comparison of different catalytic systems

Dry reforming of methane (DRM) is one of the most attractive methods for producing syngas by utilizing two major greenhouse gases: methane (CH₄) and carbon dioxide (CO₂). Among the numerous effective technologies for DRM, nonthermal plasma (NTP)-catalysis has attracted particular attention because of its ease of handling and mild operating conditions. Ni-based catalysts are widely applied in NTP-catalytic DRM because of their ability to activate and break C-C and C-H bonds. However, their practical application is often hindered by deactivation caused by carbon deposition. To develop more efficient and stable Ni-based catalysts for DRM, a comprehensive understanding of catalyst activation and the associated reaction mechanisms within the plasma environment is essential. Accordingly, this paper presents a review of the research on NTP-catalytic DRM over Ni-based catalysts. In the first section, the factors affecting the activity of Ni-based catalysts, including the catalyst preparation method, promoter, and support are described. Secondly, the plasma-induced activation mechanisms of molecules and catalysts governed by key plasma characteristics (e.g., operational parameters, e∗, active species, and thermal effects) are discussed, along with the influence of catalyst properties on discharge behavior and the reaction mechanism of NTP-catalytic DRM. It is followed by a detailed description of three different catalytic methods of DRM. Finally, suggestions for future research on NTP-catalytic DRM are provided. The findings of this review can help understand the mechanism underlying the synergistic reactions between plasma and catalysts and can serve as a guide for the future improvement of Ni-based catalysts for NTP-catalytic DRM.