Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electricity production: When enzymes rival platinum

04.09.2017

A fuel cell converts chemical energy into electrical energy via hydrogen combustion. Though it is considered to be a clean technology - because it does not emit greenhouse gases - fuel cells do use costly rare metal catalysts1, such as platinum, to oxidize hydrogen and reduce oxygen.

In recent years, the identification of biocatalysts, enzymes with remarkable properties, has revitalized research in this area: their oxygen, and especially hydrogen, transformation activity is comparable to that of platinum. Hydrogenase activity was, until recently, inhibited by oxygen and therefore incompatible with use in cells.


Biocell using H2/O2 fuel based on a heat-stable hydrogenase that resists oxygen and a carbon monoxide at the anode and a heat-stable bilirubin oxidase at the cathode that provide currents of the order of amps per milligram of enzymes.

Credit: Ievgen Mazurenko, BIP

For several years, researchers in the Laboratoire of Bioénergétique et Ingénierie des Protéines (CNRS/Aix-Marseille Université) have been developing a new generation of biocells. They have replaced the chemical catalyst (platinum) with bacterial enzymes: at the anode2, hydrogenase (key for converting hydrogen into many microorganisms), and at the cathode3, bilirubin oxidase.

They have now identified a hydrogenase that is active in the presence of oxygen and resistant to some platinum inhibitors like carbon monoxide. In collaboration with the Centre de Recherche Paul Pascal (CNRS/Université de Bordeaux), they also explored biodiversity to identify heat-stable enzymes that can withstand temperatures between 25°C and 80°C.

To shift these bioprocesses from the laboratory to industrial development two major hurdles had to be overcome. In 2014, their first prototype was limited by both the low power it generated and by lack of enzyme stability. So they needed a change of scale, yet had to retain the enzymes' activity and protect them from any inhibitors.

A third major problem was how to reduce costs, so among other things, they had to minimize the amount of enzyme used. All of these issues required fundamental and multidisciplinary study intended to shine light on the factors that limit bioelectrocatalysis.

By progressively incorporating the two heat-stable enzymes in a carbon-based architecture, the researchers solved these three problems. A carbon felt with suitably adapted porosity is the host structure for the enzymes, and also serves as protection against chemical species generated when oxygen is reduced, which change enzyme activity. So the cell can function without loss of performance for several days.

Using this controlled architecture and enzymes' intrinsic properties, the researchers have managed for the first time to quantify the proportion of enzymes participating effectively in the current, demonstrating that the currents delivered by the biocatalyst are very similar to target results for platinum.

They have also developed a numerical model to determine the cell's optimal geometry. So these biocells appear to be an alternative to classic fuel cells: biomass can be used to provide both the fuel (hydrogen) and the catalyst (the enzymes), which are by nature, renewable.

###

  1. A catalyst can activate or accelerate chemical reactions.
  2. Electrode where an oxidation reaction occurs. This is the negative pole in an electric cell.
  3. Electrode where a reduction reaction occurs. This is the positive pole in an electric cell.

Media Contact

Anne-Sophie Boutaud
anne-sophie.boutaud@cnrs.fr
33-144-964-606

http://www.cnrs.fr 

Anne-Sophie Boutaud | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht Researchers measure near-perfect performance in low-cost semiconductors
18.03.2019 | Stanford University

nachricht Robot arms with the flexibility of an elephant’s trunk
18.03.2019 | Universität des Saarlandes

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>