The FeBTC metal–organic framework (MOF) incorporated with magnetite is proposed as a novel material to solve water contamination with last generation pollutants. The material was synthesized by in situ solvothermal methods, and Fe₃O₄ nanoparticles were added during FeBTC MOF synthesis and used in drug adsorption. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy characterized the materials, with N₂-physisorption at 77 K. Pseudo-second-order kinetic and Freundlich models were used to describe the adsorption process. The thermodynamic study revealed that the adsorption of three drugs was a feasible, spontaneous exothermic process. The incorporation of magnetite nanoparticles in the FeBTC increased the adsorption capacity of pristine FeBTC. The Fe₃O₄–FeBTC material showed a maximum adsorption capacity for diclofenac sodium (DCF), then by ibuprofen (IB), and to a lesser extent by naproxen sodium (NS). Additionally, hybridization of the FeBTC with magnetite nanoparticles reinforced the most vulnerable part of the MOF, increasing the stability of its thermal and aqueous media. The electrostatic interaction, H-bonding, and interactions in the open-metal sites played vital roles in the drug adsorption. The sites’ competition in the multicomponent mixture’s adsorption showed selective adsorption (DCF) and (NS). This work shows how superficial modification with a low-surface-area MOF can achieve significant adsorption results in water pollutants.

The study of the deactivation of HY zeolites in the dehydration reaction of glycerol to acrolein has represented a challenge for the design of new catalysts. HY zeolites with SiO₂/Al₂O₃ molar ratios between 3.5 and 80 were studied. The solids were characterized by XRD, N₂ physisorption, SEM-EDXS, Raman and UV-vis spectroscopies, infrared spectroscopy of pyridine (FTIR-Py) and catalytic activity tests from 250 °C to 325 °C. It was found that the total amount of acid sites per unit area of catalyst decreased as the SiO₂/Al₂O₃ molar ratio increased from 3.5 to 80, resulting in the decrease in the initial glycerol conversion. The initial acrolein selectivity was promoted with the increase of the Brønsted/Lewis acid sites ratio at any reaction temperature. The deactivation tests showed that the catalyst lifetime depended on the pore structure, improving with the presence of large surface areas as evidenced by the deactivation rate constants. The characterization of the deactivated catalysts by XRD, N₂ physisorption and thermogravimetric analysis indicated that the deposition of coke resulted in the total obstruction of micropores and the partial blockage of mesopores. Moreover, the presence of large mesopores and surface areas allowed the amount of coke deposited at the catalyst surface to be reduced.

The addition of Pt (0.1 wt%Pt) to the 2 wt%Ag/Al₂O₃-WOx catalyst improved the C₃H₈– Selective Catalytic Reduction (SCR) of NO assisted by H₂ and widened the range of the operation window. During H₂–C₃H₈–SCR of NO, the bimetallic Pt–Ag catalyst showed two maxima in conversion: 80% (at 130 °C) and 91% (between 260 and 350 °C). This PtAg bimetallic catalyst showed that it could combine the catalytic properties of Pt at low temperature, with the properties of Ag/Al₂O₃ at high temperature. These PtAg catalysts were composed of Ag⁺, Ag_n^δ+ clusters, and PtAg nanoparticles. The catalysts were characterized by Temperature Programmed Reduction (TPR), Ultraviolet Visible Spectroscopy (UV-Vis), Scanning Electron Microscopy (SEM)/ Energy Dispersed X-ray Spectroscopy (EDS), x-ray Diffraction (XRD) and N₂ physisorption. The PtAg bimetallic catalysts were able to chemisorb H₂. The dispersion of Pt in the bimetallic catalysts was the largest for the catalyst with the lowest Pt/Ag atomic ratio. Through SEM, mainly spherical clusters smaller than 10 nm were observed in the PtAg catalyst. There were about 32% of particles with size equal or below 10 nm. The PtAg bimetallic catalysts produced NO₂ in the intermediate temperature range as well as some N₂O. The yield to N₂O was proportional to the Pt/Ag atomic ratio and reached 8.5% N₂O. WOx stabilizes Al₂O₃ at temperatures ≥650 °C, and also stabilizes Pt when it is reduced in H₂ at high temperature (800 °C).

A set of Y-type zeolites with Si/Al atomic ratios between 7–45 were studied as catalysts in the aminocyclization reaction between acrolein and ammonia to produce pyridine and 3-picoline. The catalytic activity tests at 360 °C revealed that the acrolein conversion increased in the order Z45 < ZY34 < ZY7 < ZY17, in agreement with the increase of the total acidity per gram of catalyst. In all cases, pyridine bases and cracking products (acetaldehyde and formaldehyde) were detected in the outflow from the reactor. The total yield of pyridines was inversely proportional to the total acidity for the catalysts, which presented large surface areas and micro- and mesoporosity. The selectivity towards 3-picoline was favored when using catalysts with a Brønsted/Lewis acid sites ratio close to 1. The formation of pyridine occurred more selectively over Lewis acid sites than Brønsted acid sites. The deactivation tests showed that the time on stream of the catalysts depended on the textural properties of zeolites, i.e., large pore volume and large BET area, as evidenced by the deactivation rate constants and the characterization of the spent catalysts. The physicochemical properties of the catalysts were determined by XRD, UV-vis, and Raman spectroscopies, infrared spectroscopy with adsorbed pyridine, N₂ physisorption, and SEM-EDXS. After the reaction, the spent catalysts were characterized by XRD, Raman spectroscopy, TGA, and SEM-EDXS, indicating that the uniform deposition of polyaromatic species on the catalyst surface and within the porous system resulted in the loss of activity.

Thermal and catalytic pyrolysis of waste expanded polystyrene (WEPS) was studied to obtain mainly styrene monomer, which can be recycled in the polystyrene industry. Initially, preliminary experiments were carried out in a static semi-batch glass reactor with basic catalysts and without catalysts, using toluene as solvent at 250 °C, determining their styrene yields to select the best catalyst. MgO turned out to be the best catalyst due to its stability and cost. This catalyst was characterized by XRD, BET area, SEM-EDS, Raman spectroscopy, UV–VIS, and TGA. The kinetic equation for WEPS pyrolysis in the glass reactor was determined as a first-order reaction. The heat of reaction, the Gibbs free energy change, and the entropy change were calculated. Finally, WEPS pyrolysis experiments were carried out using a rotating semi-batch steel reactor, at higher temperatures and without using solvents, evaluating the styrene yield and its performance for its possible industrial application. In this reaction, the activity remained almost constant after four catalyst regenerations. The best styrene yield was 94 wt%, which could be one of the highest reported in the literature. This result may be associated with the back-mixing obtained in the rotary reactor, in contrast to the performance observed in the static glass reactor.

This study shows the development of a combustion promoter for the oil-refining process called fluid catalytic cracking (FCC). The investigation of a catalyst prepared for the combustion of CO composed of 0.05 wt% Pt supported on SiO₂–Al₂O₃–0.5 wt% W microspheres with high mechanical resistance, promoted with tungsten oxides (WOx) that can inhibit the sintering of Pt, is reported. The addition of WOx in SiO₂–Al₂O₃ inhibited the decrease in the specific area when calcined from 550 °C to 950 °C. SiO₂–Al₂O₃ support in the form of calcined microspheres with average diameters between 70–105 µm were produced by spray drying, using two atomization discs with vanes of different geometry: a straight rectangular blade disc (DAR) and a curved rectangular vanes disc (DAC). The DAR disk produced whole microspheres, while the DAC had hollow and broken microspheres. The microspheres were characterized by XRD, SEM, optical microscopy, N₂ physisorption (BET area) and fracture resistance tests. The Pt catalysts were evaluated by TPR, H₂ chemisorption and CO combustion. The catalyst of 0.05 wt% Pt/SiO₂–Al₂O₃–0.5 wt% turned out to be the most stable. A thermal stabilization effect was observed at contents lower than 1 wt% W that allowed it to inhibit the sintering of the Pt catalyst.