A team of researchers from the Hong Kong University of Science and Technology (HKUST) has developed a new hydrogen fuel cell that is not only the longest in the world to date, but also is the most profitable. Thanks to the decrease in the amount of platinum used as an electrocatalyst by almost 80% the cost of the materials that make up the system is reduced. At the same time the new formula established a record in terms of durability for this technology.
The hydrogen fuel cell is a technology that provides a clean option as it generates power by converting hydrogen and oxygen into electricity. The result is a process with zero local emissions, since neither carbon dioxide nor particles or other pollutants that can contaminate the environment are generated. But despite these environmental benefits and many years of development, hydrogen fuel cells are still they have failed to convert in a widely traded option.
Hydrogen fuel cell technology has two fundamental handicaps to overcome. The first is the scarce existing hydrogen supply network. The system requires a network similar to the one that exists today with service stations, which is complex and expensive to implement. In addition, to achieve the sustainability of the process, the hydrogen must be green, that is, created by hydrolysis using renewable energies. The second handicap, also very important, is the cost of fuel cell systems.
Within a fuel cell, hydrogen reacts with oxygen to generate electricity, scrubbing only water as the final waste. Power generation relies heavily on an electrocatalyst that is made up largely of an expensive and rare material.the platinum. This precious metal is essential in the oxygen reduction reaction because as it is a slow process, platinum is necessary to help speed it up.
Numerous scientific studies have tried to develop alternatives, replacing platinum with more common and cheaper materials such as iron, nitrogen or carbon. However, but those materials have either been shown be inefficient in power generation or have poor durability.
Now a research team led by Professor SHAO Minhua director of the Hong Kong HKUST Institute of Energy and its Department of Chemical and Biological Engineering, has found a new formula that can not only reduce the proportion of platinum used in fuel cells by 80%but also sets a record in terms of durability.
Despite the low proportion of platinum, the new hybrid catalyst developed by this team managed to maintain the catalytic activity of platinum at a 97% after 100,000 test cycles accelerated stress. By comparison, today’s catalyst typically experiences more than a 50% drop in performance after 30,000 cycles. In another of the tests carried out, the new fuel cell did not show no decrease performance after operating for 200 hours.
One of the reasons behind these outstanding results is the fact that the new catalyst has three different active sites for the reaction, instead of just one, as is the case with current catalysts. With a formula containing atomically dispersed platinum, individual iron atoms and nanoparticles of platinum and iron, the new mixture accelerates the reaction rate and achieves catalytic activity 3.7 times higher to that of platinum itself. Theoretically, the higher the catalytic activity, the greater the power delivered by the fuel cell.
Professor Shao explains that the hydrogen fuel cell is an essential energy conversion device to achieve carbon neutrality, so there is a need to expand its use during the fight against climate change. “Thanks to the Government’s Green Technology Fund, we will look to further refine the catalyst and make it compatible with fuel cell vehicles and other electrochemical devices.”