Revealing the dependence of CO<sub>2</sub> activation on hydrogen dissociation ability over supported nickel catalysts
Tiancheng Pu, Liang Shen, Jing Xu, Chong Peng, Minghui Zhu
Abstract
Abstract In the present work, we demonstrate that the mechanism and kinetics of CO 2 activation, as the first step of its hydrogenation, over supported nickel catalysts is particle size sensitive owing to the distinct H 2 dissociation ability over nickel particles with various sizes. Large nickel nanoparticles facilitate H 2 dissociation, enabling CO 2 activation via a kinetically favored redox mechanism compared to small nickel nanoparticles that activate CO 2 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 CO 2 hydrogenation. This work demonstrated in the CO 2 hydrogenation reaction, CO 2 is activated through different mechanisms due to different H 2 dissociation capabilities over supported Ni catalysts with different particle sizes, which provides a convincing experimental explanation for the structural sensitivity of nickel‐based catalysts.