Hydrogen has great potential for helping society to reach net-zero emissions. The problem is that the most economical and established production methods for hydrogen depend heavily on fossil fuels and result in roughly a dozen kilograms of carbon dioxide emissions for every kilogram of hydrogen produced.
The carbon-free way to produce hydrogen is by splitting water into its component elements. This process generally requires the use of catalysts and lots of energy.
Researchers at the University of Oxford are developing a synthetic biology approach to the production of so-called green hydrogen. The idea is to replace expensive, exotic metal-based catalysts with a highly-efficient, stable, and cost-effective catalyst based on genetically-engineered bacteria.
There are specific microorganisms that can naturally induce the chemical reaction that reduces protons to hydrogen by the use of hydrogenase enzymes. While these reactions do occur naturally, they are limited to low hydrogen yields.
The Oxford researchers genetically engineered the bacterium Shewanella oneidensis by inserting a light activated electron pump called Gloeobacter rhodopsin as well as adding nanoparticles of graphene oxide and ferric sulfate. All of this tinkering with the bacterium resulted in a ten-fold increase in hydrogen yield.
The researchers believe that their system, based entirely on biological methods rather than traditional chemical approaches, could be scaled up to produce ‘artificial leaves’ that, when exposed to sunlight, would immediately begin producing hydrogen. The Oxford work was published last summer in the Proceedings of the National Academy of Science.
**********
Web Links
A green fuels breakthrough: bio-engineering bacteria to become ‘hydrogen nanoreactors’
Photo, posted July 27, 2016, courtesy of Blondinrikard Froberg via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
Leave a Reply