Facilitated CO2 hydrogenation by strong metal-support interaction between Ni and BaCO3

Strong metal-support interactions (SMSIs) have attracted increasing attention due to their geometric and electronic effects in improving catalytic performance. For the first time, an SMSI phenomenon between Ni and BaCO₃ was discovered. We observed the migration of BaCO₃ support onto metallic nickel nanoparticles following H₂ reduction and CO₂ hydrogenation. The resulting porous overlayer not only stabilized nickel nanoparticles from sintering but also increased the number of Ni-BaCO₃ sites. The abundant Ni-BaCO₃ sites significantly promote the adsorption and activation of CO₂. We also found that both the hydrogen atmosphere and metallic nickel nanoparticles boost the decomposition of BaCO₃, followed by its regeneration in a CO₂ atmosphere. Furthermore, the CO₂ hydrogenation atmosphere enables the sustainable decomposition-regeneration of BaCO₃, remarkedly increasing the CO₂ concentration at the Ni-BaCO₃ interface. Ultimately, the promoted CO₂ activation and localized CO₂ enrichment at the Ni-BaCO₃ interface collectively facilitate the CO₂ hydrogenation reaction.