Design of high-efficiency carbonic anhydrase mimics with well-defined Zn sites based on salphen organic framework

• Highly efficient Carbonic Anhydrase (CA) mimic was designed for CO 2 hydration. • Single-atom coordinated salphen organic framework with CA-like activity was achieved for the first time. • Systematic characterization of CA-like activities by p -nitrophenyl acetate hydrolysis was carried out. For a variety of CO 2 -related catalytic applications, developing reliable and efficient biocatalysts with carbonic anhydrase (CA)-like activities presents an appealing application potential. However, very limited progress has been made in regulating the activity of biocatalysts that can mimic the natural CA. Here, inspired by the Zn-coordination structure of CA active centers, we report a new and efficient CA-mimetic organic framework with Zn-N 2 O 2 single-atom active sites to promote CO 2 -related hydration reactions. Because of the increased atomic utilization level compared to Zn coordinated salphen organic framework, the CA-like biocatalyst exhibits ultrafast reaction kinetics in p -NPA hydrolysis ( V 0 = 317.82nM s −1 , V max = 1.28 µM s −1 , turnover number: 3.91 × 10 -3 s −1 ), which surpasses the majority of CA-mimetic biocatalysts that have been reported to date. Our research indicates that the construction of well-defined Zn centers and the improvement of atomic utilization efficiency can enhance the activity of CA-like biocatalysts and outline a new approach to regulating the catalytic activity of CA-mimicking biocatalysts for a wide range of CO 2 -related processes.