Revealing the dependence of CO2 activation on hydrogen dissociation ability over supported nickel catalysts

Abstract

AbstractIn the present work, we demonstrate that the mechanism and kinetics of CO2 activation, as the first step of its hydrogenation, over supported nickel catalysts is particle size sensitive owing to the distinct H2 dissociation ability over nickel particles with various sizes. Large nickel nanoparticles facilitate H2 dissociation, enabling CO2 activation via a kinetically favored redox mechanism compared to small nickel nanoparticles that activate CO2 via the formate mechanism. The elucidation of the dependency of the catalytic reaction pathway on particle size will guide the rational design of supported nickel catalysts for selective CO2 hydrogenation. This work demonstrated in the CO2 hydrogenation reaction, CO2 is activated through different mechanisms due to different H2 dissociation capabilities over supported Ni catalysts with different particle sizes, which provides a convincing experimental explanation for the structural sensitivity of nickel‐based catalysts.