Study of the formation of cyanide vacancies to increase the catalytic activity of Prussian blue analogues in water oxidation reactions

• Grant number: 24/23188-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2025
• End date: September 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Juliano Alves Bonacin
• Grantee: Pedro Henrique de Souza Borges
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 24/09666-6 - Study of the formation of cyanide vacancies to increase the catalytic activity of Prussian blue analogues in water oxidation reactions, AP.R

Abstract

The energy transition poses great challenges to our society not only in terms of climate-related aspects but also to the global economy and current chemical processes. Replacing fossil fuels with clean and renewable sources is an immediate necessity, given that for the first time, in 2023, the planet's temperature exceeded the pre-industrial average by 2 °C and we are observing countless climate catastrophes. Among the available alternatives, hydrogen (H2) can be considered an important option for clean energy and renewable raw materials for current chemical processes. It is important to highlight that the environmental benefits of H2 are related to its production process. It is worth noting that the production of green hydrogen, obtained from the water electrolysis process using renewable electricity, is pointed out as a sustainable option for our society. Although this process seems simple, the water oxidation reaction is the bottleneck of the process, as it is both thermodynamically and kinetically unfavorable and, therefore, requires a catalyst. Developing efficient, low-cost, and highly stable catalysts remains a significant technological challenge. Thus, the great motivation of this project continues to be the improvement of the performance of catalysts based on Prussian blue analogues (PBA) for use in water oxidation reactions (WOR) under mild conditions. In this project, we will study the influence of cyanide vacancies on the performance of Prussian blue analogues in WOR. We observed in the previous project that these vacancies create additional active sites in the PBAs and significantly improve their catalytic performance. However, we need to understand more systematically how these vacancies are formed, how to control them, and how we can optimize the performance of these new catalysts. With this, we aim to study strategies to increase the turnover frequency (TOF) values of the Prussian blue-based catalysts. We have achieved TOF values between 10-2 to 10-1 s-1 and believe we can increase these values more than 10 times. Consequently, we could place the PBAs on par with commercial catalysts. Beyond these efforts, we also seek scientific, and technological advancements, and excellence in human resource training for national development. (AU)