Sheet-Like Morphology CuO/Co 3 O 4 Nanocomposites for Enhanced Catalysis in Hydrogenation of CO 2 to Methanol.

The selective hydrogenation of CO 2 into high-value chemicals is an effective approach to address environmental issues. Cobalt-based catalysts have significant potential in CO 2 hydrogenation reaction systems; however, there is a need to control their selectivity better. In this study, copper is introduced onto Co 3 O 4 nanosheets using the ion exchange reverse loading method. The unique interaction of these materials significantly alters the selectivity of the cobalt-based catalyst. Results from scanning transmission electron microscopy and scanning electron microscopy indicate that this catalyst enables a more even dispersion of copper species in the Co 3 O 4 nanosheets. Temperature-programmed reduction and X-ray photoelectron spectroscopy reveal that the catalyst facilitates the metal-metal interaction between Co and Cu. Temperature-programmed desorption experiments for CO 2 and H 2 demonstrate that the close interaction between Co and Cu modifies CO 2 adsorption, leading to differences in catalytic activity. Moreover, the catalyst effectively suppresses CO 2 methanation and promotes methanol formation by altering the alkalinity of the catalyst surface and weakening the hydrogen dissociation ability.