ZIF-8 with a large specific surface area and its dopamine modified derivative as a carbonic anhydrase-mimicking catalyst for enhancing CO2 absorption in decarbonization solvents

Zeolitic Imidazolate Framework-8 (ZIF-8) shows potential as a carbonic anhydrase-mimicking catalyst for enhancing carbon dioxide (CO 2 ) absorption in industrial decarbonization solvents. This study synthesized ZIF-8 with high Brunauer-Emmett-Teller (BET) specific areas and their dopamine-modified hydrophilic derivatives (ZIF-8-DA) via a one-step method, aiming to maximize ZIF-8’s catalytic performance in CO₂ hydration. Both ZIF-8 and ZIF-8-DA effectively promoted CO₂ absorption in water and alkaline solvents, with excellent stability and reusability. Among them, ZIF-8-DA (220) exhibited the highest catalytic activity, achieving absorption enhancement efficiencies of 95.54% in water, 35.26% in diethanolamine (DEA) solution, and 18.42% in potassium carbonate (K₂CO₃) solution. Compared with ZIF-8, ZIF-8-DA showed better water dispersibility-a key to its higher activity. Dopamine modification significantly improved the hydrophilicity of ZIF-8, enabling stronger interactions with CO₂ in the aqueous phase and facilitating nucleophilic attack on CO₂. Importantly, the modification preserved ZIF-8’s structure, ensuring reusability across multiple absorption cycles. This research underscores that ZIF-8-DA with high BET specific area holds substantial potential as an efficient and durable carbonic anhydrase- mimicking catalyst for industrial CO₂ capture.