Composition Optimization and Mechanism Study of High Entropy Alloys for Ammonia Production through Experiment Design and Synchrotron Radiation Techniques

• Grant number: 25/07234-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2026
• End date: December 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Raphael Nagao de Sousa
• Grantee: Luiz Otávio Orzari
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country, AP.PCPE

Abstract

Ammonia is a key molecule in the modern world, being widely produced by the Haber-Bosch process. This is an aggressive protocol for reducing H2 with N2, under highly energetic conditions, with high temperature and pressure. In addition, modern industrial plants also consume fossil fuels to generate H2. Alternatives to this method are a concern of the scientific community, especially considering the search for cleaner energy sources, for which ammonia is also an excellent candidate. One of the options, which has proven to be considerably more sustainable, is production by electrochemical means, especially the nitrate reduction reaction (NO3RR). This route also has other advantages, such as a lower reaction overpotential and the possibility of using wastewater as a source of nitrate, making it more environmentally friendly, by returning stability to the nitrogen cycle. The literature presents efficient catalysts for this purpose, but high-entropy alloys (HEAs) have recently gained attention due to their improved performance. As alloys composed of at least five principal metals, their stable form presents high values of structural entropy, which allows them unique possibilities: the synergy between the metals can provide amplified effects in relation to the sum of the properties, and multiple stages of the NO3RR can occur simultaneously. Although very attractive, these alloys are exceptionally complex, which has led to more restrictive studies regarding their mechanisms. This project aims to study and optimize the functioning of HEAs with the help of Design of Experiments and Synchrotron radiation techniques, which will allow the statistical description and modeling of the relationship between the composition and the preferred functioning mechanisms for the production of ammonia. (AU)