Enhancement of formic acid production from CO2 in formate dehydrogenase reaction using nanoparticles

Abstract

In an enzyme reaction using a gas substrate, the slow gas–liquid mass transfer rate of the gas substrate limits the total reaction rate, which causes low productivity. In this study, magnetic nanoparticles of cobalt ferrite silica (MSNs) and methyl-functionalized cobalt ferrite silica (methyl-MSNs) were synthesized and applied to a CO₂–water system to evaluate gas–liquid mass transfer. The addition of methyl-MSNs increased the solubilized CO₂ concentration by 31.1% compared to a 5.9% increase by MSNs. In an experiment where methyl-MSNs were added, the volumetric mass transfer coefficient was 78.3% higher than that in a control experiment without nanoparticles. The addition of methyl-MSNs in the formate dehydrogenase reaction resulted in a 12.0% increase in formic acid production and could decrease the reaction time required to finish the batch enzyme reaction from 1.5 h to 1.0 h. This result showed that the addition of methyl-MSNs could be useful for biological processes, including enzyme reactions, when using a gas substrate to improve productivity.