Designing catalysts based on isolated metal sites for nitrate reduction reaction: unveiling the (photo)electroactivity, stability and selectivity of materials for green amonnia production

• Grant number: 25/06157-6
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Maria Valnice Boldrin
• Grantee: Matheus Schiavon Kronka
• Supervisor: Marc Ledendecker
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Institution abroad: Technical University of Munich, Straubing (TUM), Germany
• Associated to the scholarship: 23/17739-0 - The impact of modified amorphous carbon with sub-nanometric particles on the electro(photo)catalytic reduction of nitrate in aqueous media towards targeted production of NH3 or N2, BP.PD

Abstract

This research project focus on the development of catalytic materials for the electrochemical reduction of nitrate (NO3RR) to enable sustainable ammonia (NH3) production and environmental remediation. The conventional Haber-Bosch process for NH3 synthesis is energy-intensive and environmentally detrimental, driving the need for greener alternatives. NO3RR offers a promising solution by utilizing nitrate, a common water pollutant, as a nitrogen source. However, achieving high selectivity for NH¿ over competing byproducts like nitrogen gas (N2) remains a significant challenge. To address this, we propose the design and synthesis of single-atom catalysts (SACs) based on transition metals (Ni, Cu, Pd and Ag) supported on nitrogen-doped carbon and semiconductor oxides (e.g., WO¿, TiO2). These materials are engineered to optimize metal-support interactions and enhance electron transfer by using photoelectrochemical processes. The use of metal acetylacetonate (M-Acac) precursors and the tuning the support material are proposed to achieve individually dispersed metal atoms with stabilization, preventing agglomeration and maximizing active site exposure. By systematically tuning the composition, structure, and electronic properties of these catalysts, we aim to improve the faradaic efficiency, selectivity for NH3 production, and overpotential required for NO3RR. This work not only advances the development of sustainable NH¿ production but also contributes to the remediation of nitrate-contaminated water, addressing critical environmental and agricultural challenges.