Hypercrosslinked polymers (HCPs) for CO2 capture and catalytic conversion: synthesis, functionalization, and applications

Abstract

The escalating concentration of atmospheric carbon dioxide (CO₂), primarily driven by fossil fuel consumption, presents critical challenges to environmental sustainability and climate change mitigation. Catalytic conversion of CO₂ into valuable products (e.g., carbon monoxide (CO), methanol, and cyclic carbonates) offers a promising strategy for addressing these challenges. Among diverse catalysts, hypercrosslinked polymers (HCPs) have emerged as efficient and versatile platforms for CO₂ capture and conversion, owing to their high surface area, tunable porosity, chemical stability, and ease of functionalization. This review comprehensively explores the potential of HCPs in sustainable CO₂ management. We discuss key synthesis strategies for HCPs (post-crosslinking, self-crosslinking, external crosslinker knitting, and solvent knitting) and functionalization approaches (pre-functionalization, post-modification, and composite formation) designed to optimize their CO₂ adsorption capacity and catalytic performance. The mechanisms and applications of HCPs in CO₂ capture (via physisorption and chemisorption) and catalytic conversion (including photocatalytic, electrocatalytic, and chemical conversion), and their roles in composite materials for enhanced activity are critically examined. Challenges related to reaction efficiency, selectivity, and catalyst stability are addressed. Finally, future research directions are proposed to advance HCP-based systems for practical CO₂ capture and utilization in energy and environmental applications.