A new method of extracting hydrogen from water more efficiently could help underpin the capture of renewable energy in the form of sustainable fuel, scientists say.
In a new paper, published today in the journal Nature Communications, researchers from universities in the UK, Portugal, Germany,and Hungary describe how pulsing electric current through a layered catalyst has allowed them to almost double the amount of hydrogen produced per millivolt of electricity used during the process.
Electrolysis, a process which is likely familiar to anyone who studied chemistry at high school, uses electric current to split the bondsbetween the hydrogen and oxygen atoms of water, releasing hydrogen and oxygen gas. If the electric current for the process ofelectrolysis is generated through renewable means such as wind or solar power, the entire process releases no additional carbon intothe atmosphere, making no contributions to climate change. Hydrogen gas can then be used as a zero-emission fuel source in someforms of transport such as buses and cars or for heating homes.
The teams research focused on finding a more efficient way to produce hydrogen through the electrocatalytic water-splitting reaction. They discovered that electrodes covered with a molybdenum telluride catalyst showed an increase in the amount of hydrogen gasproduced during the electrolysis when a specific pattern of high-current pulses was applied By optimising the pulse of currentthrough the acidic electrolyte, they could reduce the amount of energy needed to make a given amount of hydrogen by nearly 50%.
Dr Alexey Ganin, of the University of Glasgows School of Chemistry, directed the research team. Dr Ganin said: "Currently the UKmeets about a third of its energy production needs through renewable sources, and in Scotland, that figure is about 80%.
Experts predict that we"ll soon reach a point where we l be producing more renewable electricity than our consumption demands.However, as it currently stands the excess of generated energy must be used as it's produced or else it goes to waste. Its vital that wedevelop a robust suite of methods to store the energy for later use.
Batteries are one way to do that, but hydrogen is a very promising alternative. Our research provides an important new insight intoproducing hydrogen from electrolysis more effectively and more economically, and were keen to pursue this promising avenue of Investigation.
Since the level of catalytic enhancement is controlled by electric currents, recent advances in machine learning could be used to finetune the right sequence of applied currents to achieve the maximum output. The next stage for the team is the development of anartificial intelligence protocol to replace human input in the search for the most effective electronic structures use in similar catalyticprocesses.
The paper, titled The rapid electrochemical activation of Mote2 for the hydrogen evolution reaction, is published in Nature Communications. The research was conducted at the University of Glasgow, the University of Kie, the University of Lisbon, and the Hungarian Academy of Sciences and was supported by funding from the Engineering and Physical Sciences Research Council(ESPRC)and the Carnegie Trust.