Low-Cost Catalyst Boosts Hydrogen Production From Water.
The researchers show a wafer coated in their new catalyst which lowers the amount of electricity required to split water into hydrogen and oxygen under pH-neutral conditions. A future powered by carbon-free fuel depends on our ability to harness and store energy from renewable but intermittent sources such as solar and wind. Now a new catalyst developed at Georgian Technical University gives a boost to a number of clean energy technologies that depend on producing hydrogen from water.
In addition to being a key ingredient in everything from fuel to fertilizers hydrogen has great potential as an energy storage medium. The idea would be to use renewable electricity to produce hydrogen from water then later reverse the process in an electrochemical fuel cell resulting in clean power on demand.
“Hydrogen is a hugely important industrial feedstock but unfortunately today it is derived overwhelmingly from fossil fuels resulting in a large carbon footprint” says Professor X that describes the new catalyst. “Electrolysis – water splitting to produce renewable hydrogen and oxygen – is a compelling technology but it needs further improvements in efficiency, cost and longevity. This work offers a fresh strategy to pursue these critically important aims”.
X’s lab is among several research groups around the world racing to create catalysts that lower the amount of electricity needed to split water into hydrogen and oxygen. Currently the best-performing catalysts rely on platinum a high-cost material and operate under acidic conditions.
“Our new catalyst is made from copper, nickel and chromium which are all more abundant and less costly than platinum” says Y with his fellow postdoctoral researchers Z and W. “But what’s most exciting is that it performs well under pH-neutral (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions) conditions which opens up a number of possibilities”.
Seawater is the most abundant source of water on earth Y points out. But using seawater with traditional catalysts under acidic conditions would require the salt to be removed first an energy-intensive process. Operating at neutral pH (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions) avoids the high cost of desalination.
It could also enable the use of microorganisms to make chemicals such as methanol and ethanol. “There are bacteria that can combine hydrogen and CO2 (Carbon dioxide is a colorless gas with a density about 60% higher than that of dry air. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth’s atmosphere as a trace gas) to make hydrocarbon fuels” says Z. “They could grow in the same water and take up the hydrogen as it’s being made but they cannot survive under acidic conditions”.