Hydrogen-fueled CO2 reduction using oxygen-tolerant oxidoreductases

Abstract

Hydrogen gas obtained from cheap or sustainable sources has been investigated as an alternative to fossil fuels. By using hydrogenase (H2ase) and formate dehydrogenase (FDH), H2 and CO2 gases can be converted to formate, which can be conveniently stored and transported. However, developing an enzymatic process that converts H2 and CO2 obtained from cheap sources into formate is challenging because even a very small amount of O2 included in the cheap sources damages most H2ases and FDHs. In order to overcome this limitation, we investigated a pair of oxygen-tolerant H2ase and FDH. We achieved the cascade reaction between H2ase from Ralstonia eutropha H16 (ReSH) and FDH from Rhodobacter capsulatus (RcFDH) to convert H2 and CO2 to formate using in situ regeneration of NAD+/NADH in the presence of O2.

Real flue gas CO2 hydrogenation to formate by an enzymatic reactor using O2- and CO-tolerant hydrogenase and formate dehydrogenase

“…Formate production was quantified via HPLC. The retention time of formate was 13.010 min ( Cha et al, 2023a ). No formate was produced in the reactor without ReSH.…”

“…Strains and expression conditions of ReSH and MeFDH1 were described in previous studies ( Jang et al, 2018 ; Cha et al, 2023a ). To purify ReSH, cell pellets were resuspended in 50 mM potassium phosphate (Kpi) buffer (pH 7.0) containing 1 mg/mL lysozyme to a concentration of 1 g/10 mL.…”

“…We previously demonstrated the feasibility of the combined use of O 2 -tolerant H 2 ase and FDH using pure gases ( Cha et al, 2023a ). However, for CO 2 hydrogenation using the real flue gas, several issues should be solved.…”

Effect of Hydrogen Charging on the Mechanical Properties of High-Strength Copper-Base Alloys, Austenitic Stainless Steel AISI 321, Inconel 625 and Ferritic Steel 1.4511

“…Hydrogen as an eco-friendly energy source is considered a cornerstone for meeting the climate targets stated within the "Paris Agreement" by reducing carbon dioxide emissions when used as a substitute for fossil fuels [1][2][3][4][5]. However, large-scale hydrogen technologies are still in the development phase since several different challenges must be addressed, such as the production and generation of sufficient amounts of pure hydrogen, hydrogen storage and transportation as well as the actual combustion processes.…”

Local Hydrogen Measurements in Multi-Phase Steel C60E by Means of Electrochemical Microcapillary Cell Technique

“…Hydrogen is considered an eco-friendly energy source. By utilizing pressurized hydrogen within the industry, a significant reduction in carbon dioxide emissions can be achieved [1,2]. Simultaneously, there is an increasing demand for lightweight construction, especially within the automotive industry.…”