Síntese e caracterização de novos materiais para captura e utilização de CO2

Abstract

The use of technologies that involve the CO2 capture, storage and utilization, is pointed out as fundamental to reduce the concentrations of CO2 in the atmosphere. However, some challenges still need to be overcome for the efficient use of these technologies, such as the development of new materials that involve low production cost and energy expenditure, are recyclable and efficient in the CO2 capture/separation step as well as heterogeneous catalysts in the chemical transformation of CO2. In this context, the present work brings the synthesis and characterization of silica xerogels and synthetic silica-metallic mineral particles (SSMMP), pristine and grafted with ILs. These new materials were tested as adsorbents in the CO2 capture and separation and as heterogeneous catalysts in the reactions of CO2 conversion into cyclic carbonates. The synthesized materials were characterized by XRD, TGA, FTIR, RAMAN, BET, SEM and NMR. The selectivity of solid sorbents and the selectivity of the cycloaddition reactions were analyzed by GC. SSMMP-M1 (2,07 mmolCO2/gads) and SSMMP-Ni50%- AMO Br (1,63 mmolCO2/gads), presented higher CO2 sorption capacity and SSMMP 5%Im(nBu)-I (16,9) and SSMMP-Ni 50%-IMI Br (14,4) the best selectivity capacity for CO2 in CO2/N2 mixtures. As heterogeneous catalysts, the best yields of cyclic carbonate were observed for samples SX-EMIM MSO3 4 and SSMMP-Ni 50% with yields of propylene carbonate of 91.4% and 90.4%, respectively. For both applications, the samples have excellent recyclability, without loss of catalytic activity and CO2 sorption for up to 10 consecutive recycles.