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

• Grant number: 23/17739-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2024
• Status: Discontinued
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Maria Valnice Boldrin
• Grantee: Matheus Schiavon Kronka
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies, AP.TEM
• Associated scholarship(s): 25/06157-6 - Designing catalysts based on isolated metal sites for nitrate reduction reaction: unveiling the (photo)electroactivity, stability and selectivity of materials for green amonnia production, BE.EP.PD

Abstract

High levels of nitrates and derived nitrogen compounds have increased considerably in wastewater and superficial water bodies, significantly impacting aquatic ecosystems through the process of eutrophication (excessive growth of algae and aquatic plants that consume dissolved O2). Therefore, the present project seeks to investigate new electro(photo)catalytic materials to be used in the selective reduction of NO3¯ for the generation of ammonia (for economic purposes) or the removal of contamination via reduction to gaseous nitrogen (for effluent treatment purposes).For this purpose, the goal is to build carbon paper electrodes (diffusion layer electrodes) and "silicon wafers" with p-type semiconductor characteristics, as a support for amorphous carbon (Printex L6 or Vulcan XR-72).They will be modified with deposits of metallic nanoparticles on a sub-nanometer scale of Ti, Nb, W, Cu, Ag and Au, in order to reduce the potential of nitrate reduction electrocatalytic and photoelectrocatalytic properties of these materials.The produced catalysts will be characterized by conventional techniques, and the generated products during the electrocatalytic and/or photoelectrocatalytic reduction of nitrate will be monitored by ion chromatography techniques.The processes efficiency and the reaction selectivity should be monitored and compared during the electrolysis performed at a controlled potential over time without and with LED light irradiation in reactors with a quartz window. Also in the project, we intend to investigate the modification of the electrode surface using polymers with intrinsic microporosity (PIM) in order to study the effect of pre-concentration of nitrate on the electrode surface in terms of process efficiency. Finally, after optimizing the electrodes, the ones that perform best will be applied to aqueous solutions purposely contaminated with nitrate and transferred to more realistic systems involving the collection of wastewater containing excess nitrate.