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Oregon State University (OSU) researchers have developed advanced catalysts for clean hydrogen production. Catalysts are used in industries to speed up a chemical reaction. They make the production of several materials easier, quicker and more efficient. Their studies have shown that clean hydrogen can be produced with much higher efficiency and at a low cost as compared to hydrogen production with commercially available catalysts.
What Have Researchers Found?
Catalysts are substances that increase the rate of a chemical reaction without undergoing any permanent change in themselves. “In facilitating reaction processes, catalysts often experience changes in their structure,”said Zhenxing Feng, a chemical engineering professor at OSU. Sometimes, the changes are irreversible, and other times reversible. An irreversible restructuring is the main cause of the degradation of a catalyst’s stability, leading to the loss of its activity that decreases the reaction efficiency.
Maoyu Wang, Feng, a Ph.D. student at OSU, and other researchers studied the catalysts’ structure changes in reaction and then manipulated their composition and surface structure at the atomic level for achieving a highly efficient catalytic process for hydrogen production.
Iridium hydroxide is the most widely used commercial catalyst. Industries prefer this catalyst over others due to its less reactivity, toxicity, solubility and environmental impact. Given its wide acceptability and rampant use in the industry, researchers chose this catalyst for their experiments.
In their study, an active phase (working phase of catalyst) based on amorphous (irregular shape) iridium hydroxide showed efficiency up to 150 times that of its original structure and a high reaction magnitude (3rd order) which is better than the commercial catalyst, iridium oxide.
“We discovered at least two groups of materials that undergo irreversible changes and turned out to be useful catalysts for hydrogen production”, said Feng. “This can allow us to generate hydrogen at $2 per kilogram and then at $1 per kilogram that is less costly than the other polluting agents emitted by the industries. This study can help us to achieve the United States zero-emission goal by 2030.”
Here, polluting agents refer to the poisonous gases emitted by the industries. This can include carbon dioxide, nitrogen, carbon monoxide, sulfur, etc. These gases ultimately lead to global warming that further causes natural disasters. Therefore, researchers are looking forward to using hydrogen as a clean energy source that does not produce these pollutants. This research can help to boost hydrogen production to satisfy the energy demands of industry and hence public at large.
Feng remarks that the United States Department of Energy Hydrogen and Fuel Cell Technology Office has set a standard for clean hydrogen production at $2 per kilogram by 2025 and $1 per kilogram by 2030 as part of the Hydrogen Energy Earth shot target of reducing the clean hydrogen cost by 80%, from $5 to $1 in a single decade.
Feng’s team is focused on water electrolysis technology to produce clean hydrogen. This process uses electricity from renewable resources to break water into its components to generate clean hydrogen. The efficiency of water electrolysis is low due to high overpotential (the difference between the theoretical and actual potential in an electrochemical reaction), he said.
“Catalysts are critical to promoting the water-splitting reactions by lowering the overpotential, and thus lowering the total cost for hydrogen production,” said Feng. “Our first research in JACS Au established a foundation for us, and now we have demonstrated how we can manipulate the atoms in the catalysts to make them according to the requirements in our Science Advances article”.
The article in JACS Au describes the complete or partial structural changes in catalysts during electrochemical reactions. These changes increase their activity that help to fasten the chemical processes. Moreover, this study helped Feng and his team to carry forward their experiments in the right direction.
Why Is This Research Important?
According to Feng, the outcomes of the study are important because hydrogen production plays a crucial role in every aspect of life, such as the manufacture of different chemicals from ammonia, fuel cells for cars, refining of metals, production of man-made articles like plastics and other products.
“Producing hydrogen by water electrolysis is a cleaner and sustainable way as compared to the traditional methods of extracting hydrogen from natural gas via methane-steam reforming. However, the cost of green technology can be an obstacle in the market,” he added.
The new findings can help to design the catalysts in such a way that they can enhance the efficiency of the hydrogen production process and lower its cost.