Direct conversion of waste CO₂ over porous polymer catalysts

Direct conversion of waste CO₂ avoids CO₂ capture and lowers the cost of CO₂ utilisation; however, this route remains a challenging research topic. Developing catalysts that facilitate the enrichment and conversion of waste CO₂ is therefore essential. Porous polymer catalysts offer unique advantages due to their high surface area and tunable functionality. These materials catalyse the conversion of both simulated waste CO₂ and CO₂ present in industrial waste gases, such as anaerobic fermentation gas, lime kiln waste gas, and coal-fired flue gas. This review summarises recent progress on the direct conversion of waste CO₂ using porous polymer catalysts. It analyses the structural features of these catalysts, their CO₂ adsorption properties, and the associated catalytic mechanisms. A quantitative comparison of catalytic performance-such as turnover frequency, stability, and CO₂ adsorption capacity-is also provided. The findings may support the rational design and synthesis of catalysts for the direct utilisation of waste CO₂, and provide parameters for the industrialisation of porous polymer catalysts.