One-pot synthesis of efficient carbonic anhydrase-zeolitic imidazolate framework-8 composite for enhancing CO2 absorption

Carbonic anhydrase (CA) enzyme-based absorption process is under development for CO 2 capture. How to maintain the activity and stability of CA enzyme is the important issue related to this emerging process. The immobilization technologies are regarding as the promising method to stabilize CA in harsh environments. This work encapsulated CA into zeolitic imidazolate framework-8 (ZIF-8) with different particle sizes according to several preparation protocols and investigated their activity and stability. The experimental results revealed that the preliminary crystallization time, enzyme dosing amount, and particle sizes of ZIF-8 had a significant influence on the catalytic performance of immobilized CA. The remaining activity of the CA after immobilization ranged from 52 to 93 % depending on the employed preparation protocol. In addition, the immobilized CA with particle size of ∼400 nm exhibited better activity compared to those with particle sizes of ∼100 nm and 1000 nm. Moreover, with the increase of the preliminary crystallization time, the stability of immobilized CA descended.