A team of researchers discovered a way to produce hydrogen through electrolysis that will make the process cheaper and more efficient.
Everyday science works to find cleaner energy sources so that we would let go of the carbon-emitting energy sources we are using now, reduce our carbon footprint and save the environment. By now, everyone has heard of the most favored renewable energy sources (wind, water, sun), but there is one “clean” energy source that is slowly turning into an economy by itself even though it is not as publicized as the others: Hydrogen. Hydrogen can be found in many compounds we use on a daily basis, including some compounds we are already using for fuel such as coal, petroleum, natural gas and water. Recently, it was discovered that hydrogen might be beneficial in more ways than just as fuel. The production of hydrogen emits almost no greenhouse gas, and once hydrogen is produced, it generates electricity in a fuel cell but emits only vapor and water. In other words, it is clean to produce and use. Furthermore, the fact that hydrogen can be produced from so many different sources means that any country that can produce it will have energy security. The challenges appear when we consider the two common methods of producing hydrogen: stem-methane reforming and electrolysis.
Steam-methane reforming is used when trying to produce hydrogen from hydrocarbon compounds such as petroleum or natural gas, or biofuels. The method calls for high-temperature steam (1,300˚F-1,800˚F) that is forced on methane (CH4) at a pressure of 3-25 bar, in the presence of a catalyst. The reaction emits not only hydrogen but also carbon dioxide in small quantities and carbon monoxide. Although this method is the cheapest way to produce hydrogen, it is not the cleanest. The second common way of producing hydrogen is electrolysis: the process of splitting hydrogen from water using an electric current. This method only emits hydrogen and oxygen if the electricity used comes from natural sources like the sun, wind or water, and a little bit of carbon if the source is a fossil fuel. The issue with this method is with building the cost of building the infrastructure to produce the electricity used in the electrolysis and the environment for the reaction itself. Luckily, a team of researchers from the Australian National University found a solution for both challenges.
Dr. Siva Karuturi and Dr. Heping Shen found a way to produce hydrogen through electrolysis without an external source of electricity and any carbon emission. Their technique is dubbed the solar-to-hydrogen approach because here, instead of using the electricity produced by solar panels, they used the sunlight directly. The approach also reduced the cost of electrolysis by using inexpensive materials as semiconductors. The material used here is a combination of perovskite cells with specially designed Si electrode to absorb the sunlight. To ensure its stability, the perovskite cell has been improved by Dr. Shen, who is an expert in perovskite. The solar-to-hydrogen electrolysis also uses noble-metal such as platinum, but the researchers are already at work to find a cheaper alternative. With their methods, the researchers increase the energy conversion efficiency of electrolysis to a level (17.6 percent conversion rate) that is close to that of a solar panel (20 percent conversion rate).
Dr. Karuturi believes that they will reach the 20-percent mark in the coming months, which means that the solar-to-hydrogen electrolysis might become the least expensive way of producing hydrogen. Thanks to this new discovery, Australia will be able to export hydrogen, putting the country ahead in the race for cleaner and better energy sources.
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