Abstract CuCrO2 was synthesized by solution combustion synthesis (SCS) and applied as a heterogeneous catalyst to produce soybean biodiesel. The combustion reaction was carried out using urea as a fuel, and copper (II) and chromium (III) nitrates as precursors. After the powders’ obtention, these were calcined and functionalized in an acidic medium. The powders were characterized by thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), and infrared spectroscopy (IR) techniques. The TG curve revealed that the formation of the CuCrO2 in the combustion reaction remained stable up to 1000 °C. The XRD results confirmed the formation of the CuCrO2 compound. The SEM images showed that the crystallinity of the samples increased after the calcination process. The IR spectra showed the presence of delafossite characteristic bands. After the transesterification reaction, biodiesel was obtained with a yield of around 80%. Thus, catalysts based on delafossite synthesized through the combustion method and functionalized showed to be promising for the transesterification reaction of vegetable oils. CuCrO SCS (SCS fuel II (II III (III precursors obtention medium TG, , (TG) Xray X ray XRD, (XRD) SEM, (SEM) (IR techniques 100 C °C compound process bands 80 80% Thus oils (TG (XRD (SEM 10 8 1

Resumo A capacidade de adsorção de CO2 em materiais mesoporosos com estruturas diferentes foi avaliada. Para este efeito, MCM-48 e SBA-15 impregnados com níquel em proporções de 5%, 10% e 20% (m/m) foram utilizados. Os resultados mostraram que a impregnação com níquel promoveu um aumento da interação entre o CO2 e a superfície do material. Os dados foram ajustados utilizando o modelo de Freundlich. As variações de energia livre de Gibbs e entropia do sistema de adsorção foram avaliadas. A termodinâmica de adsorção mostrou que o processo é espontâneo. A partir do modelo de Freundlich concluiu-se que existe uma forte interação do CO2 com os sítios dos materiais impregnados.

Abstract The adsorption capacity of CO2 in mesoporous materials with different structures was evaluated. For this purpose, MCM-48 and SBA-15 impregnated with nickel in proportions of 5, 10 and 20 wt% were used. The results showed that impregnation of nickel promoted an increased interaction between CO2 and the surface of the material. Data were fitted using the Freundlich model. Gibbs free energy and entropy changes of the adsorption system were evaluated. Thermodynamics of adsorption showed that the process is spontaneous. From the Freundlich model, it was concluded that there is a strong interaction of CO2 with sites of the impregnated materials.