Porous crystalline frameworks for thermocatalytic CO2 reduction: an emerging paradigm†
Heterogeneous catalysts for CO2 reduction derived from porous, crystalline frameworks have emerged as efficient systems with comparable activity and superior selectivity to their inorganic counterparts. The spatial arrangement of active sites in such catalytically active frameworks is critical to their performance in CO2 reduction. This review presents a comprehensive and critical analysis of (thermal) CO2 reduction over catalysts derived from porous, crystalline frameworks, whose structural and chemical diversity offers unprecedented opportunities to regulate reactivity. Thermodyamic considerations and the impact of process parameters on reaction intermediates, governing mechanisms for CO2 reduction and catalyst stability are discussed. Strategies for leveraging the flexibility of porous, crystalline frameworks to improve their stability and promote CO2 reduction are presented which include: use as sacrificial precursors to an active phase; integration within composites; and as hosts for nanoparticle encapsulation. Finally, future challenges and research prospects are highlighted.