Confinement Effects in Well-Defined Metal-Organic Frameworks (MOFs) for Selective CO2 Hydrogenation: A Review

Decarbonization has become an urgent affair to restrain global warming. CO2 hydrogenation coupled with H-2 derived from water electrolysis is considered a promising route to mitigate the negative impact of carbon emission and also promote the application of hydrogen. It is of great significance to develop catalysts with excellent performance and large-scale implementation. In the past decades, metal-organic frameworks (MOFs) have been widely involved in the rational design of catalysts for CO2 hydrogenation due to their high surface areas, tunable porosities, well-ordered pore structures, and diversities in metals and functional groups. Confinement effects in MOFs or MOF-derived materials have been reported to promote the stability of CO2 hydrogenation catalysts, such as molecular complexes of immobilization effect, active sites in size effect, stabilization in the encapsulation effect, and electron transfer and interfacial catalysis in the synergistic effect. This review attempts to summarize the progress of MOF-based CO2 hydrogenation catalysts up to now, and demonstrate the synthetic strategies, unique features, and enhancement mechanisms compared with traditionally supported catalysts. Great emphasis will be placed on various confinement effects in CO2 hydrogenation. The challenges and opportunities in precise design, synthesis, and applications of MOF-confined catalysis for CO2 hydrogenation are also summarized.

Automated summary

This article summarizes the progress of MOF-based CO2 hydrogenation catalysts, emphasizing the various confinement effects of MOFs in CO2 hydrogenation. The article points out that MOFs are widely used in the rational design of CO2 hydrogenation catalysts due to their high surface area, tunable porosity, ordered pore structures, and diverse metals and functional groups. The confinement effects in MOFs promote the stability of CO2 hydrogenation catalysts and have various mechanisms, such as immobilization effect, size effect, encapsulation effect, and synergistic effect. In summary, MOF catalysts have significant potential for applications in CO2 hydrogenation.