Influence of the Support on Ni Catalyst Response During Plasma‐Driven CO ₂ Methanation

ABSTRACT

Selecting an appropriate support is critical for tuning the characteristics that influence catalyst performance. While numerous supports have been studied for thermal‐catalytic systems, understanding of the support property–activity relationships in plasma‐catalytic systems remains limited. The current study examines the influence the characteristics of four distinct supports—Al ₂ O ₃ , CeO ₂ , BaTiO ₃ , and SrTiO ₃ —have on the performance of a 5 wt% nickel catalyst during plasma‐catalytic CO ₂ methanation. In the absence of the Ni catalyst, the supports exhibited methanation activity and CH ₄ selectivity in a 150°C plasma environment, highlighting the capacity of the support for facilitating the CO ₂ methanation reaction. With an Ni catalyst present, Ni/CeO ₂ delivered the highest plasma‐catalytic activity, and all catalysts exhibited greater than 90% CH ₄ selectivity. Gas‐phase species present during plasma‐catalytic methanation were similar for each catalyst, confirming that activated species generation was not appreciably impacted by the support. Mapping support characteristics with catalyst activity indicated that CO ₂ adsorption capacity and the ability to facilitate Ni reduction are more significant than surface area and govern catalytic performance by influencing Ni dispersion. The study illustrates the importance of selecting a support with characteristics favorable for the reaction being targeted in a plasma‐catalytic environment, akin to appropriate catalyst selection for thermal‐catalytic scenarios.