Functionalization of Au Eletrocatalysts by Imidazole Dithiocarbamate Derivatives: Exploring the Molecular Junction as Strategy for Electroreduction of Carbon Dioxide.

• Grant number: 18/10415-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2018
• End date: February 28, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fabio Henrique Barros de Lima
• Grantee: Maykon Lima Souza
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion, AP.TEM

Abstract

The electrocatalytic reduction of carbon dioxide (CO2) is a key theme on the global research concerning stock and energy conversion. Due the multidisciplinary of the problem, these investigations apply concepts from different sciences. For instance, the functionalization of metallic surfaces by organic molecules is considered an elegant and efficient strategy to modulate the catalytic activity of electrodes. In this project is proposed the exploration of the CO2 electroreduction control in aqueous media by modify Au electrodes surfaces with dithiocarbamates (DTC) containing imidazole and aliphatic carbon chains. The strategy is based on: 1) Solid evidences that DTC (R2N-CS2-) form stronger interaction in metal surface than thiols (RSH), thermally more stable, more resistant to acid and basic pHs, and generate stronger electronic coupling; 2) Pyridine (pyr) anchored on Au electrode was reported to increase the selectivity of the electroreduction of CO2 to HCOO- owing the pyr/pyrH+ species (pKa ~ 5.2); 3) The imidazolium cation (ImNH+) in polymers, promotes the stabilization of the anion radical of carbon dioxide (CO2*-) and favor its electroreduction to CO; 4) The use of imidazole-DTC having aliphatic carbon chains (-CnH2n+1) with different lengths, provides a simple way to modulate the hydrophobic feature of the molecular junction on the metallic surface. Such strategy might be used to control the access of H+ ions to the surface and consequentially the generation of H2 and other hydrogenated products, like HCOO-. The Au electrocatalysts containing DTCs derivatives of the methylamine Imidazole-CnH2n+1 (n = 0, 5 e 8) will be synthesized in the laboratory and faradic efficiencies will be calculated by means of the determination of the reaction products in on-line and in-line experiments, via mass spectrometry and gas chromatography, respectively.

Scientific publications

(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)

QUEIROZ, ADRIANA C.; SOUZA, MAYKON L.; CAMILO, MARIANA R.; SILVA, WANDERSON O.; CANTANE, DANIEL A.; MESSIAS, IGOR; PINTO, MARIA R.; NAGAO, RAPHAEL; LIMA, FABIO H. B.. Electrochemical Mass Spectrometry: Evolution of the Cell Setup for On-Line Investigation of Products and Screening of Electrocatalysts for Carbon Dioxide Reduction. CHEMELECTROCHEM, v. 9, n. 12, p. 15-pg., 2022-05-23. (20/15230-5, 18/10415-7, 19/22183-6, 09/07629-6, 16/13323-0, 17/11986-5, 16/01817-9, 14/26699-3, 19/08244-2)

SOUZA, MAYKON L.; LIMA, FABIO H. B.. Dibenzyldithiocarbamate-Functionalized Small Gold Nanoparticles as Selective Catalysts for the Electrochemical Reduction of CO2 to CO. ACS CATALYSIS, v. 11, n. 19, p. 12208-12219, OCT 1 2021. (16/13323-0, 19/22183-6, 13/07296-2, 18/10415-7, 13/16930-7)