Activation of OER catalysts based on binuclear ruthenium complexes by hydrogen bonding groups

• Grant number: 18/04523-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2018
• End date: July 20, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Koiti Araki
• Grantee: Kalil Cristhian Figueiredo Toledo
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/24725-4 - Supramolecular chemistry and nanotechnology, AP.TEM
• Associated scholarship(s): 19/27046-7 - Development, validation and application in mechanistic, structural and electronic proprieties of metal complexes using microjet XPS Spectroelectrochemical cells, BE.EP.PD

Abstract

The sustainable production of clean, easy-to-store and carbon-free fuels that can meet the needs of future generations is one of the most important scientific challenges of the 21st century. The conversion of solar energy into electricity and especially in chemical energy using photoelectrochemical cells and artificial photosynthetic systems, particularly the photodecomposition of water in H2 and O2, is a possible goal. In this context, the Oxygen Evolution Reaction (OER) is a tetra-electronic and tetraprotonic reaction that is limiting the efficiency of fuel cells and solar fuel production still. In fact, catalysts that can meet the needs for stability and efficiency have not yet been found, such that innovative strategies need to be developed to improve the understanding of the reaction mechanism, thus making it possible to reduce the high overpotential associated with O2 formation, thus making possible the realization of artificial photosynthetic systems and the storage of solar energy as high energy chemicals.Among the several materials, ruthenium complexes are promising alternatives as OER catalysts. In recent years, mononuclear complexes have been explored intensively, but it has been shown that even in these cases the reaction mechanism involves the formation of a binuclear activated complex. Thus, in this project we focused in the preparation and study of binuclear ruthenium complexes derived from the 2,6-bis(2-pyridyl)benzodiimidazole ligand, whose structures were adjusted to tune the interaction of a water molecule with the two active sites, through the interaction with hydrogen bonding groups such as -OH and -CN, strategically positioned in between the ruthenium complexes, to facilitate the formation of the I2M activated complex and increase the catalytic efficiency, while exploiting the susceptibility of the bridging ligand to PCET reactions to decrease the potential for formation of the catalytically active high valence species. Finally, the catalysts will be connected with materials capable of favoring photoinduced charge separation reactions such as TiO2 semiconductor oxide films, or photosensitizers derived from the [Ru(bpy)3]2+ complex in order to realize photosynthetic systems for solar fuel production. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FRANCO, LEANDRO REZENDE; TOLEDO, KALIL CRISTHIAN FIGUEIREDO; MATIAS, TIAGO ARAUJO; ARAUJO, C. MOYSES; ARAKI, KOITI; COUTINHO, KALINE. Theoretical investigation of solvent and oxidation/deprotonation effects on the electronic structure of a mononuclear Ru-aqua-polypyridine complex in aqueous solution. Physical Chemistry Chemical Physics, v. 25, n. 36, p. 20-pg., 2023-09-20. (17/11631-2, 18/21489-1, 18/04523-1, 21/09016-3, 17/50129-0)

FRANCO, LEANDRO REZENDE; TOLEDO, KALIL CRISTHIAN FIGUEIREDO; MATIAS, TIAGO ARAUJO; ARAUJO, C. MOYSES; ARAKI, KOITI; COUTINHO, KALINE. Theoretical investigation of solvent and oxidation/deprotonation effects on the electronic structure of a mononuclear Ru-aqua-polypyridine complex in aqueous solution. Physical Chemistry Chemical Physics, v. N/A, p. 20-pg., 2023-08-22. (17/11631-2, 18/21489-1, 18/04523-1, 21/09016-3, 17/50129-0)

GONCALVES, JOSUE M.; MATIAS, TIAGO A.; TOLEDO, KALIL C. F.; ARAKI, KOITI; VANELDIK, R; HUBBARD, CD. Electrocatalytic materials design for oxygen evolution reaction. WATER OXIDATION CATALYSTS, v. 74, p. 63-pg., 2019-01-01. (18/04523-1, 13/24725-4)

SILVA, JOSE LUIS; UNGER, ISAAK; MATIAS, TIAGO ARAUJO; FRANCO, LEANDRO REZENDE; DAMAS, GIANE; COSTA, LUCIANO T.; TOLEDO, KALIL C. F.; ROCHA, TULIO C. R.; DE BRITO, ARNALDO NAVES; SAAK, CLARA-MAGDALENA; et al. X-ray Photoelectron Fingerprints of High-Valence Ruthenium-Oxo Complexes along the Oxidation Reaction Pathway in an Aqueous Environment. Journal of Physical Chemistry Letters, v. 10, n. 24, p. 7636-7643, DEC 19 2019. (18/04523-1, 17/11986-5, 13/24725-4, 17/11631-2, 17/50129-0)