Solar to Liquid Fuels Production: Light-Driven Reduction of Carbon Dioxide to Formic Acid
Abstract
Project FA9550-09-1-0671 involved generating formic acid from CO2 using sunlight as the source of energy. The method chosen was to engineer a Photosystem I-molecular wire-formic acid dehydrogenase (FDH) bioconjugate that would carry out the half-cell reaction CO2 + 2e + 2H+ + 2h H2CO2. The work had three specific goals: (Aim 1) to generate a Cys Gly variant of the Escherichia coli FDH enzyme to provide a point of attachment for a molecular wire; (Aim 2) to modify Photosystem I (PS I) from Synehocystis sp. PCC 6803 so that electrons can be withdrawn from a point in the electron transfer chain that would provide the requisite redox potential for CO2 reduction at atmospheric concentrations; and (Aim 3) to construct a PS I-molecular wire-FDH bioconjugate that would function as a direct light-driven CO2 to formic acid photo-electrochemical half-cell. Aim 1 was successful in that a catalytically-active C42G variant of FdhF was generated that contained a cysteine rather than a selenocysteine (U140C). Aim 2 was also successful in that a naphthoquinone-containing molecular wire consisting could be introduced into the A1A and A1B sites of the menB variant of PS I and could transfer 134 electrons mg Chl-1 h-1 to an external catalyst in the light.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 29, 2014
- Accession Number
- ADA599519
Entities
People
- Amanda Applegate
- Carolyn E. Lubner
- Donald A. Bryant
- John H. Golbeck
- Michael Gorka
Organizations
- Pennsylvania State University