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In this work, a sulfated titanium dioxide (STi) catalyst obtained from a commercial TiO2 precursor was synthesized and characterized. The catalyst was sulfated by the simple impregnation method with H2SO4 and subsequently calcined at different temperatures. The synthesized catalyst was characterized by X-ray Diffraction (XRD), Energy-Dispersive Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). The sulfated catalyst was thermally treated at different temperatures (100, 200, 400, and 600 °C) and evaluated in oleic acid esterification reactions by varying the concentration of the catalyst during the conversion of oleic acid to methyl oleate. The conversion was measured from the variation of the acid index (AI)° and free fatty acids (FFA) during the reaction. The STi catalyst obtained was compared with two homogeneous catalysts, H2SO4 and ferric sulfate [Fe2(SO4)3], evaluating the reaction time in the conversion, from which improvements in the reaction performance of the catalyst synthesized in this work were observed versus the two homogeneous catalysts mentioned earlier. Catalyst reuse cycles were also evaluated as well as their performance in the esterification of waste cooking oil. The best catalyst yields reached values close to 86% in a reaction time of 6 h.

This work shows the results obtained in the synthesis of srilankite nanoparticles, (Zr, Ti)O2, and TiO2 anatase, both catalysts presented an admix of phases, anatase/rutile, and srilankite/rutile, respectively. Their performance in the production of biodiesel through the esterification of oleic acid was evaluated. The catalysts were obtained using the sol-gel process and sulfated via the impregnation method. The samples were characterized using X-ray diffraction (XRD), scan electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier-Transform Infrared Spectroscopy (FTIR) to analyze the properties in its crystalline structure, morphology, and chemical composition. Its efficiency during the esterification reaction was measured based on the decrease in free fatty acids (FFA). FFA, oleic acid was added at different weight percentages (1%, 3%, and 5% w/w). The time of reaction was 6 hours at 55 °C and the catalyst with better performance was the sulfated Srilankite/rutile, reaching a maximum conversion of up to 90%.

Two series of Cu/Co/Cr modified Fischer–Tropsch catalyst promoted with Zn or Mn and an alkaline metal (Me: Li, Na, K, Rb, Cs) were prepared by co-precipitation method and tested for high alcohol synthesis (HAS) at one hour on-stream and at two temperatures, 300 and 350 °C. The results indicate that the best selectivity toward high alcohols depends on temperature and catalysts composition and is obtained as follows: a) at 300 °C over catalysts without Zn and containing K, Na and Rb; b) at 350 °C over catalysts without Zn and containing K; c) at 350 °C over catalysts containing Zn as well as Li and Cs. Two series of Cu/Co/Cr modified Fischer–Tropsch catalyst promoted with Zn or Mn and an alkaline metal (Me: Li, Na, K, Rb, Cs) were prepared by co-precipitation method and tested for HAS at one hour on-stream and at two temperatures, 300 and 350 °C. The results indicate that the higher HA production (i.e. normal and branched butanol) is obtained at 350 °C over catalysts promoted with Zn and all alkali metals, except for Li which shown its best performance at 300 °C.

Two series of sulfated zirconia catalysts promoted with Pt and Pt–Ni, respectively, were prepared and extruded with different amount of alumina binder (0, 20, 33, and 60 wt%). The catalytic activities of the two series of catalysts, SZPtA and SZNiPtA, were measured for n-pentane isomerization reaction. The reaction reaches its maximum conversion at 20 wt% of alumina for both catalyst series. Adding alumina beyond 20 wt% reduces the overall conversion and modifies the selectivity for both catalysts series from i-C4 towards i-C5 suggesting that the reaction mechanism changed from a monomolecular to a bimolecular one. However, only SZNiPtA catalysts maintain a higher catalytic activity at higher amounts of alumina. Such difference between the two catalyst series can be attributed to the combining effect of Ni and Pt promotion of the SZNiPtA catalysts and not to their acidic properties.

Sulfated mixed oxides, SO 4 = /Ni–Al–O and SO 4 = /Zr–Al–O were evaluated for double bond isomerization (DBI) of 1-hexene using helium and hydrogen as carrier gases. The increase of temperature from 100 to 200 °C seems to favor the deprotonation pathway and contribute to increase the 1-hexene conversion for both catalysts and without regard of the carrier gas. The results indicate that temperature it is the main factor that contributes to improve both conversion and selectivity towards (cis + trans)-2-hexene, while the reductive atmosphere beneficiate only the SO 4 = /Ni–Al–O catalyst performance, as hydrogen prevents this catalyst from a fast deactivation.

Improvement of the sulfated zirconia catalysts (SZN) was studied by adding different amounts of alumina as follows: 17.5, 29.8, 45.9, and 56wt %. Even though, alumina, is expect to promote higher specific area and increase the amount of acid sites, stability of the zirconia tetragonal phase, the active zirconia phase of the SZN catalyst isisomerization reaction was obtained for catalysts containing between 17.5, and 29.8wt % of alumina, which reflects the promotional effect of alumina. On the contrary, a strong reduction of this reaction rate is observed when higher amounts of alumina are added to the catalyst, which indicates the dilution effect of alumina.

Trifluoromethanesulfonic acid (triflic acid) and montmorillonite type clay were used to prepare a super acid sulfonic clay (SASC) with Ho