Green hydrogen has established itself as one of the fundamental energy pillars for tackling the climate crisis and advancing global decarbonization. Unlike fossil fuels, its production is clean; when consumed in energy processes, its only by-product is water. Furthermore, hydrogen holds three times more energy than conventional fuels. Recent research indicates that hydrogen produced by electrolysis using renewable energy could reduce greenhouse gas emissions by between 50% and 90% compared to fossil fuel methods without carbon capture.
To harness this vast potential, Chile presented its National Green Hydrogen Strategy in 2020, aiming to position the country as a worldwide leader in this industry by 2030. The plan leverages Chile's compelling comparative advantages in renewable energy: the intense solar radiation of the Atacama Desert and the strong winds of the far south. This facilitates the cost-effective generation of clean electricity for subsequent hydrogen production using water electrolysis. The primary challenge, however, remains reducing production costs, particularly those associated with the use of expensive, traditional catalysts such as platinum.
In this critical context, research led by Dr. Víctor Jiménez Arévalo, and published in the international journal Materials Design, proposes an alternative to traditional catalysts. The study, titled "Recent advances in high-entropy alloys for electrocatalysis: From rational design to functional performance,” advocates for the use of High Entropy Alloys (HEAs). These novel materials are composed of at least five abundant and inexpensive metals, such as copper and molybdenum, both produced domestically. HEAs form unique and stable solid structures with superior catalytic properties that can be designed and optimized to significantly improve process efficiency.
The impact of this work is two-fold: on one hand, it directly contributes to the National Green Hydrogen Strategy by offering a route to lower production costs and making Chilean hydrogen more competitive globally. On the other hand, it fosters the development of proprietary domestic technology. Dr. Jiménez Arévalo emphasizes the necessary next step: "We have the natural resources and human capital. The challenge is to create a university-business ecosystem that allows us to manufacture our own equipment instead of just importing it.”
“Chile has unique conditions to advance in this area, with enormous potential in wind and solar energy that can be transformed into the electricity needed to ‘electrocute water’ and produce green hydrogen," the researcher explained. "This catalysis process requires plates made of noble metals such as platinum, the cost of which is one of the main barriers."
High Entropy Alloys
This is where the relevance of "high entropy" alloys lies, a concept developed independently in 2004 by Jien-Wei Yeh at National Tsing Hua University and Brian Cantor at the University of Oxford. These alloys, obtained by combining five or more metals in similar proportions, form a single solid solution that avoids the inherent fragility of traditional alloys.
“With colleagues from the north, such as Dr. Felipe Galleguillos from the University of Atacama and Dr. Pablo Martin from the Federico Santa María Technical University, we are testing high-entropy alloys in powder form to compact them and form the electrodes," explained Dr. Jiménez Arévalo. "Interestingly, we are also exploring versions manufactured using 3D printing, which opens up new possibilities for their application.”
Each high-entropy alloy is formed from several metals that, when combined, lose their individual identity to give rise to a completely new and homogeneous structure. This means that elements such as iron or copper no longer behave as individual metals but become part of a solid, uniform whole, resulting in superior catalytic properties and significantly optimizing the electrolysis process.
Science with a Purpose
Dr. Víctor Jiménez Arévalo holds a PhD in Chemistry from the University of Santiago de Chile and is a postdoctoral researcher specializing in the synthesis and study of high-entropy alloys. His career has been developed at the frontier between chemistry and metallurgy, starting as a research assistant at the University of Manchester and consolidated with his doctoral thesis, “Superficial Electrochemical Study of a High Entropy Alloy,” the only one on this subject in Chile.
He has also published in journals such as Advanced Engineering Materials and is currently applying to publish in the prestigious International Journal of Minerals, Metallurgy and Materials, proposing a new area of research for Usach.
Dr. Jiménez Arévalo concluded, emphasizing the public university's role: “As a public university, we aspire for this knowledge to have a real impact on people's lives. My vision is not focused solely on macroeconomics or hydrogen exports, but on bringing this technology to social housing and hospitals, where it can ensure heating and energy supply. That is where science truly fulfills its purpose.”