Development of photocatalytic routes for the reduction of CO2 in supercritical media.

• Grant number: 23/08424-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2024
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Cauê Ribeiro de Oliveira
• Grantee: Allef Leite dos Santos
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil
• Associated research grant: 18/01258-5 - Novel chemical catalytic and photocatalytic processes for the direct conversion of methane and CO2 to products, AP.TEM
• Associated scholarship(s): 24/20216-2 - New directions for the Photocatalytic Reduction of CO2: Biphasic Liquid-scCO2 system, BE.EP.DR

Abstract

The process of reducing CO2 with photocatalysts has been a subject of research, with promising materials such as Cu2O already being investigated. Although the reduction process utilizing water oxidation as an associated oxidative process is well known, its primary limitation lies in the interaction of CO2 with photocatalysts, as the solubility of CO2 in water is very low, leading to the emergence of H2. Thus, using a supercritical CO2 medium would permit the reaction to occur under extreme CO2-catalyst interaction conditions, i.e., the reaction medium would be the reactant itself, and the controlled addition of H2O would allow the reaction to be regulated. Thus, the project seeks to comprehend the process of CO2 reduction under supercritical conditions, i.e., supercritical CO2 as the reaction medium to which a controlled quantity of the sacrificial molecule (electron donor) will be added. The project will involve the development of a reaction cell (which must be able to withstand 74 bar and 32 °C for supercritical conditions) with a polymethylmethacrylate window that allows Cu2O catalysts to be irradiated with visible light (solar simulator), as well as the evaluation of the reaction conditions for optimizing product yield and increasing selectivity. Additionally, the effect of other sacrificial molecules will be analyzed, witnessing how the absence or low concentration of H2O can inhibit the evolution of H2 and increase energy conversion efficiency.