Limits...
Direct Electrochemical Addressing of Immobilized Alcohol Dehydrogenase for the Heterogeneous Bioelectrocatalytic Reduction of Butyraldehyde to Butanol.

Schlager S, Neugebauer H, Haberbauer M, Hinterberger G, Sariciftci NS - ChemCatChem (2015)

Bottom Line: However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor.We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH.The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH.

View Article: PubMed Central - PubMed

Affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz Altenbergerstraße 69, 4040 Linz (Austria).

ABSTRACT

Modified electrodes using immobilized alcohol dehydrogenase enzymes for the efficient electroreduction of butyraldehyde to butanol are presented as an important step for the utilization of CO2-reduction products. Alcohol dehydrogenase was immobilized, embedded in an alginate-silicate hybrid gel, on a carbon felt (CF) electrode. The application of this enzyme to the reduction of an aldehyde to an alcohol with the aid of the coenzyme nicotinamide adenine dinucleotide (NADH), in analogy to the final step in the natural reduction cascade of CO2 to alcohol, has been already reported. However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor. Immobilization of such dehydrogenase enzymes on electrodes and direct pumping of electrons into the biocatalysts offers an easy and efficient way for the biochemical recycling of CO2 to valuable chemicals or alternative synthetic fuels. We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH. The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH. Production of butanol was detected by using liquid-injection gas chromatography and was estimated to occur with Faradaic efficiencies of around 40 %.

No MeSH data available.


Liquid-injection gas chromatograms before and after electrolysis with butyraldehyde using a gel-modified electrode with immobilized alcohol dehydrogenase. At the retention time of 3.64 min a peak appears after electrolysis, indicating butanol generation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4471636&req=5

fig03: Liquid-injection gas chromatograms before and after electrolysis with butyraldehyde using a gel-modified electrode with immobilized alcohol dehydrogenase. At the retention time of 3.64 min a peak appears after electrolysis, indicating butanol generation.

Mentions: To prove the formation of butanol by the reduction process, electrolysis experiments were performed for 8 h at −600 mV vs. Ag/AgCl. Samples of the electrolyte solution before and after electrolysis were analyzed by using liquid-injection gas chromatography. The comparison of the chromatograms before and after electrolysis is shown in Figure 3. At the retention time of butanol (3.64 min) a peak is observed according to the formation of this substance during the reduction process (the small peak at 3.59 min is related to GC-sample handling and has no significance on butanol detection). From quantitative analysis of the GC measurements an amount of 20 ppm butanol in 20 mL electrolyte solution was detected, which is calculated as 5.4×10−6 moles. Analyzing the current versus time curve (Figure 4), 2400 mAs were calculated from the area enclosed by the curve, which corresponds to 2.4 Coulombs (Q) consumed during electrolysis over 8 h at −600 mV vs. Ag/AgCl. The number of moles, n, can be determined by using the following equation:1


Direct Electrochemical Addressing of Immobilized Alcohol Dehydrogenase for the Heterogeneous Bioelectrocatalytic Reduction of Butyraldehyde to Butanol.

Schlager S, Neugebauer H, Haberbauer M, Hinterberger G, Sariciftci NS - ChemCatChem (2015)

Liquid-injection gas chromatograms before and after electrolysis with butyraldehyde using a gel-modified electrode with immobilized alcohol dehydrogenase. At the retention time of 3.64 min a peak appears after electrolysis, indicating butanol generation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4471636&req=5

fig03: Liquid-injection gas chromatograms before and after electrolysis with butyraldehyde using a gel-modified electrode with immobilized alcohol dehydrogenase. At the retention time of 3.64 min a peak appears after electrolysis, indicating butanol generation.
Mentions: To prove the formation of butanol by the reduction process, electrolysis experiments were performed for 8 h at −600 mV vs. Ag/AgCl. Samples of the electrolyte solution before and after electrolysis were analyzed by using liquid-injection gas chromatography. The comparison of the chromatograms before and after electrolysis is shown in Figure 3. At the retention time of butanol (3.64 min) a peak is observed according to the formation of this substance during the reduction process (the small peak at 3.59 min is related to GC-sample handling and has no significance on butanol detection). From quantitative analysis of the GC measurements an amount of 20 ppm butanol in 20 mL electrolyte solution was detected, which is calculated as 5.4×10−6 moles. Analyzing the current versus time curve (Figure 4), 2400 mAs were calculated from the area enclosed by the curve, which corresponds to 2.4 Coulombs (Q) consumed during electrolysis over 8 h at −600 mV vs. Ag/AgCl. The number of moles, n, can be determined by using the following equation:1

Bottom Line: However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor.We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH.The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH.

View Article: PubMed Central - PubMed

Affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz Altenbergerstraße 69, 4040 Linz (Austria).

ABSTRACT

Modified electrodes using immobilized alcohol dehydrogenase enzymes for the efficient electroreduction of butyraldehyde to butanol are presented as an important step for the utilization of CO2-reduction products. Alcohol dehydrogenase was immobilized, embedded in an alginate-silicate hybrid gel, on a carbon felt (CF) electrode. The application of this enzyme to the reduction of an aldehyde to an alcohol with the aid of the coenzyme nicotinamide adenine dinucleotide (NADH), in analogy to the final step in the natural reduction cascade of CO2 to alcohol, has been already reported. However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor. Immobilization of such dehydrogenase enzymes on electrodes and direct pumping of electrons into the biocatalysts offers an easy and efficient way for the biochemical recycling of CO2 to valuable chemicals or alternative synthetic fuels. We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH. The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH. Production of butanol was detected by using liquid-injection gas chromatography and was estimated to occur with Faradaic efficiencies of around 40 %.

No MeSH data available.