Effects of modification of silica gel and ADH on enzyme activity for enzymatic conversion of CO2 to methanol

CO2 can be converted to MeOH through an enzymatic approach in three steps: (1) converting CO2 to HCOOH by formate dehydrogenase (FateDH), (2) converting HCOOH to HCHO by formaldehyde dehydrogenase (FaldDH) and (3) converting HCHO to MeOH by alcohol dehydrogenase (ADH). Polyethylene glycol (PEG) was used to adjust the pore size of immobilization carrier silica gel and SC-PEG was used to improve the catalytic property of ADH. The catalytic properties of pegylated ADH were investigated using the conversion of HCHO to MeOH as model reaction. The results show that PEG modification of the silica matrix and/or the ADH significantly increases the enzymatic activities.