Metal-Organic Polyhedra (MOPs) as emerging class of metal-organic frameworks for CO2 photocatalytic conversions: Current trends and future outlook

• Published in: Journal of CO2 utilization 2024-02, Vol.80, p.102664, Article 102664
• Main Authors: Adeola, Adedapo O., Ighalo, Joshua O., Kyesmen, Pannan I., Nomngongo, Philiswa N.
• Format: Article
• Language: English
• Subjects: CO2 conversion; Heterostructures; Metal-organic polyhedra; Photocatalysis; Post-synthetic modifications
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2023.102664

Metal-Organic Polyhedra (MOP) is a relatively new class of metal-organic frameworks, and their budding application as photocatalysts for catalytic conversion of CO2 with high activity and specificity has been reported in the last five years. However, challenges such as catalytic stability, the deactivation of active sites, and reusability concerns limit their industrial application. To mitigate these challenges, post-synthetic modifications (PSM) of MOP have proven useful without significantly altering the catalytic activity of the metal-organic framework. PSM can occur at metal centres, organic linkers, and via salt metathesis/ion exchange. These three scenarios are discussed, and useful photosensitive modifiers are highlighted. This study also highlights the potential for homogeneous catalysts to form chemical bonds with or within heterogeneous MOPs to improve CO2 transformation to CO and formic acid with 131 h-1 and 76 h-1 turnover frequencies, respectively. There is a surge in published articles on the application of functionalized MOPs in energy storage, sensors, and membrane separation in the form of hydrogels, dendrimers, hybrid composites and other heterostructures. This suggests the enormous potential of MOPs as building blocks for porous materials. Hence, the development of stable MOP via one-pot synthesis techniques and industrial-scale applications in green energy production and environmental remediation should be further investigated. •Designing MOPs with chemical and thermal stabilities is the core challenge of MOP applications.•PSM using organic linker exchange, metathesis/ion exchange and surface functionalization have addressed stability challenges.•CO2 transformation to CO and formic acid with 131 h-1 and 76 h-1 turnover frequencies have been reported.•Paucity of reports on MOP-aided CO2 conversion to value-added chemicals presents scientific research opportunities.