The hybrid fuel cell can use a wide variety of biomass sources, including starch, cellulose, lignin – and even switchgrass, powdered wood and algae.
The new solar-induced direct biomass-to-electricity hybrid fuel cell was described in the journal Nature Communications.
The challenge for biomass fuel cells is that the carbon-carbon bonds of the biomass – a natural polymer – cannot be easily broken down by conventional catalysts, including expensive precious metals. To overcome that challenge, scientists have developed microbial fuel cells in which microbes or enzymes break down the biomass. But that process has many drawbacks, including power output from such cells is limited and microbes or enzymes can only selectively break down certain types of biomass.
Researchers bypassed those issues by altering the chemistry to allow an outside energy source to activate the fuel cell’s oxidation-reduction reaction.
They say the system provides major advantages, including combining the photochemical and solar-thermal biomass degradation in a single chemical process, leading to high solar conversion and effective biomass degradation.
The system can use soluble biomass, or organic materials suspended in a liquid. In experiments, the fuel cell operated for as long as 20 hours, indicating that the POM catalyst can be re-used without further treatment.