Lysine-modulated synthesis of enzyme-embedded hydrogen-bonded organic frameworks for efficient carbon dioxide fixation

Carbonic anhydrase (CA) is an important carbon fixation enzyme. Immobilization of CA can expand its application in the realm adsorption, catalysis, and so on. As a typical metal-free framework, hydrogen-bonded organic frameworks (HOFs) featuring mild synthesis process, exquisite framework structure good enzyme compatibility have been used for embedding. However, catalytic performance CA-embedded HOFs (CA@HOFs) limited by micropore size slow adsorption CO2. Herein, CA@Lys-HOF-1 was synthesized introducing lysine (Lys), basic amino acid, during coprecipitation CO2 fixation. The addition Lys enlarged average pore HOF-1 from 1.8 to 3.2 nm, whereas introduced -NH2 groups increased initial 0.55 1.21 cm3 g-1. Compared CA@HOF-1, activity enhanced 71.25%, corresponding production CaCO3 12.7%. After eight reaction cycles, still maintained output 9.97 mg every 5 min, 83.7% production. It hoped that reported offers platform efficient continuous