Al-modified (chemical grafting) SBA-15 (SiO2/Al2O3 = 5 mass ratio) materials were used as noble metal (NM, monometallic Pt or Pd and bimetallic Pd/Pt = 4, 0.5 wt % loading) carriers. The materials were studied by XRF, N-2 physisorption, XRD, TPR, pyridine thermodesorption FTIR, and STEM (HAADF). Hydrogenating properties were tested in naphthalene (N) conversion; meanwhile, dibenzothiophene (80 ppm) was added in some experiments to evaluate the thioresistance of prepared catalysts. Al-incorporation provided enhanced Lewis and Br & oslash;nsted acidity to pristine SBA-15 due to alumina-like domains that contributed to Pt dispersion reflected in augmented hydrogenation. The Pt-based catalyst was the most active in N saturation (T = 290 degrees C, P = 6.97 MPa), whereas the Pd/Pt (4/1) formulation had enhanced thioresistance probably due to NM alloying (electron transfer in Pt-Pd core-shell particles) in conjunction with weak Br & oslash;nsted acidity (Si-O-Al bonds, electron transfer from NM) that provided additional sites for aromatic adsorption. Enhanced thioresistance is crucial for aromatic saturation of NM catalysts aimed at second-stage polishing of ultralow S diesel.

Strategies followed to improve SBA-15 surface (essentially inert) included modifications by adding acidic or basic (or both) species during or after silica synthesis. Amphoteric properties are especially important, as some reactions (alcohol dehydration, for instance) require both types of sites to efficiently take place. In this work, single Zr (nominal 3, 5, and 10 wt%, as ZrOCl2•8H2O) direct addition during SBA-15 synthesis was used to impart amphoteric characteristics (as determined by NH3 and CO2 TPD) to mesostructured SiO2 matrices. Additional materials characterization included textural (N2 physisorption) and structural (XRD, FTIR, and UV–Vis spectroscopies, and HRTEM as well) studies. Actual solids composition was also determined (EDS). The degree of Zr incorporation into mesoporous silica was enhanced with nominal content in binary formulations, although not necessarily integrated into SBA-15 walls forming Zr-O-Si linkages. It seemed that single ZrO2 domains (framework and extra-framework) could provide suitable amphoteric properties by significantly increasing the number and strength of both acid and basic sites (especially formulations containing nominal 5 wt% Zr), as to those over mesostructured silica matrices. Also, potentially deleterious strong acid sites were avoided. The binary oxides present great potential to be applied in reactions requiring vicinal acid–base pairs (alcohol dehydration, for instance).

Lanthanum (La) integration (at various nominal contents) in SBA-15 prepared under acidic medium was intended from corresponding direct nitrate addition during mesoporous silica formation. Materials were impregnated with Pt (1.5 wt%) and studied through several textural (N2 physisorption), structural (XRD, TG-DTG), and surface (FTIR, STEM-HAADF, SEM-EDS, NH3, and CO2 TPD) instrumental techniques. Pt-impregnated solids were tested in phenol hydrodeoxygenation (HDO, T = 250 °C, 3.2 MPa, batch reactor, n-decane as solvent). Catalytic activity (in pseudo-first-order kinetic constant, kHDO basis) was not directly related to Pt dispersion, which was not determined by nominal rare earth content. Determining the actual composition of modified SBA-15 materials is crucial in reaching sound conclusions regarding their physicochemical properties, especially when La modifier is directly added during mesoporous matrix formation, where efficient interaction among constituents could be difficult to get. Otherwise, results from some characterization techniques (N2 physisorption and FTIR, for instance) could be misleading and even contradictory. Indeed, extant modifier precursors, when under SBA-15 synthesis conditions, could affect the properties of prepared materials even though they were absent in obtained formulations. Performing simple compositional analysis could eliminate uncertainties regarding the role of various modifiers on characteristics of final catalysts. However, several groups have failed in doing so.

The stability of the catalyst used in hydrodeoxygenation (HDO) of biomass-derived oils needs improvement. La has been applied in delaying Al2O3 phase-change under reaction conditions. Lanthanum (0.5-8 wt.%)-gamma-alumina was studied as Pt (1 wt.%) carrier aimed at guaiacol (GUA) HDO. Materials characterization included N-2 physisorption, X-ray diffraction (XRD), thermal analysis, FTIR, UV-vis, and TPR. Solids pore size (similar to 8-10 nm) was suitable for GUA (kinetic diameter similar to 0.668 nm) hydrotreating. Mixed carriers were amorphous (XRD), suggesting well-dispersed La domains; meanwhile, carbonates/bicarbonates were formed (from CO2) due to the basic surface properties of modified supports (FTIR). That could impart catalyst stability by inhibiting coking through the passivation of Lewis acidity on Al2O3. Pt reducibility increased with La loading in various formulations. However, that was not reflected in enhanced GUA HDO (T = 488 K and P = 3.2 MPa, batch reactor), presumably due to the strong metal-support interaction (SMSI), where LaOx covered the metallic Pt particle surface. GUA HDO on various catalysts was approximated by pseudo-first-order kinetics (integral regime, k), where deviations were observed as La loading increased, presumably by an SMSI state that could affect the rate-determining step of the reaction mechanism. Basic sites provided by rare-earth could contribute to altering HDO reaction pathways as well. At 1 wt.% rare-earth, GUA HDO was maximized (k similar to 25% higher than that on Pt/Al2O3), with that material also exhibiting similar deoxygenation (85%-90% at total GUA conversion) to the latter Pt over pristine alumina. Conversely, both parameters significantly diminished over the catalyst of the highest La content. Materials at low rare-earth concentrations deserve further studies focused on catalyst stability under HDO conditions.

Al2O3-supported noble metal (NM)-modified hydrodesulfurization (HDS) catalysts (W 15.8 wt% and Ni 3.5 wt%) were applied in refractory 4.6-dimethyl-dibenzothiophene elimination. Corresponding Ru-doped (0.5 and 0.7 wt %) materials were either dried (120 degrees C) or dried followed by calcining (400 degrees C) after NM deposition prior to activation (400 degrees C, 15/85H(2)S/H-2 mixture). In solid at 0.5 wt% NM calcined after Ru deposition ruthenium was less dispersed (XRD and TPR) than over corresponding just dried one. Also, WS2 had higher dispersion (HR-TEM) on the latter. However, "NiWS " phase was enhanced (XPS) on the former material. NM-doped catalysts annealed before activation showed significantly enhanced activity (x2.4 and x1.6, solids with 0.5 and 0.7 wt% Ru, respectively) in refractory dibenzothiophene (DBT) HDS, as to that of pristine NiW/Al2O3. Enhanced hydrogenating properties of the former materials improved S elimination from sterically-hindered DBT. Conversely, Rudoping was detrimental on NiW/alumina when non-annealed prior to activation. Unreduced Run+ and decreased pyrite-like RuS2 species (XPS) on those catalysts could be related to their strongly diminished HDS activity.

This work aimed to determine the carrier effect on anisole hydrodeoxygenation (HDO, batch reactor at 573 K, and 4 MPa of H2) on 5 wt% Ni catalysts on TiO2 and TiO2-ZrO2 carriers. Besides, a TiO2-supported Ru-doped catalyst was also tested. Differences in surface acid sites, Ni reducibility, oxygen vacancies, and interactions among metals and support were detected. For instance, Ru addition promoted Ni reducibility due to improved hydrogen adsorption and subsequent spillover effect. Methoxycyclohexane and cyclohexanol were the main products over Ni/TiO2. Ru incorporation increased the initial reaction rate (×3) compared with non-doped Ni/TiO2 favoring benzene selectivity. Ni/TiO2-ZrO2 exhibited higher HDO activity and enhanced acidity than the material supported on TiO2, and high deoxygenated compounds yield a fully hydrogenated compound (cyclohexane) as well. Therefore, it was possible to promote the desired reaction pathway to relevant chemical compounds that are associated with both the support type and the metallic phase composition.

Saccharose (SA) and citric acid (CA) were used as additives in P-doped CoMo/Al2O3 catalysts (Mo, Co and P at 12, 3, and 1.6 wt%, respectively) intended to be applied in guaiacol hydrodeoxygenation (HDO). One-pot impregnating solutions were prepared by MoO3 digestion in aqueous H3PO4, followed by C4H6CoO4•4H2O addition. Organics were added (SA/Co=1, CA/Co=2) at two different preparation stages to assess the effect of that step on catalysts properties. Method I: SA or CA was added in as-prepared Co-Mo-P impregnating solution, followed by pore-filling impregnation of alumina support. Method II: SA or CA at aforementioned concentrations was impregnated on the pristine carrier, followed by drying (120 °C, 2 h). Co-Mo-P phases were further deposited on modified supports through corresponding one-pot solutions. All materials were dried (120 °C) but not calcined. Cobalt complexation by CA and Mo-blue LMCT complex formation (SA-modified solids) were identified (UV-vis, oxidic samples). Partially reduced molybdenum (Mo6+ => Mo5+, by XPS) was observed after either organics addition that effect being more evident in SA-modified solids. Materials were gas-phase sulphided (H2S/H2 10%, 400 °C, 2 h) then studied by HR-TEM. Co-Mo-P phases impregnation in one-pot solution simultaneously deposited with SA rendered the materials of the highest MoS2 dispersion.

Oil-derived middle distillates (straight-run gas oil and mixture with light cycle oil and coker gas oil) for Ultra-Low Sulfur Diesel (ULSD) production by HyDroTreating (HDT) were pretreated by selective Nitrogen Organic Compounds (NOC) adsorption. Highly crystalline Metal-Organic Framework (MOF) MIL-101(Cr) prepared with propylene oxide (proton scavenger) as textural improver was used to that end. MOF was characterized by N 2 physisorption, X-ray diffraction, thermal analysis, infrared, Raman and UV-vis spectroscopies, and electron microscopy (SEM and HR-TEM). NOC removal was carried out at room temperature and atmospheric pressure, the adsorbent being easily regenerable under mild conditions. Extruded MOF efficiently removed NOC from real feedstocks to concentrations ~ 80 ppm which allowed ULSD production at much milder conditions to those used during pristine feedstocks HDT. Operating temperature could be significantly diminished (from 350 to 330 °C, at 56 kg cm −2 (5.77 MPa), LHSV = 1.5 h −1 , H 2 /oil = 2500 ft 3 bbl −1 (445 m 3 m −3 )) which could notably prolong cycle life of NiMo/Al 2 O 3 formulation used.

The Pickering emulsion polymerization of styrene (St), divinylbenzene (DVB) as a crosslinking agent, and sodium 4-vinyl benzene sulfonate (VBS) used for in situ surface-modification of silica nanoparticles (SNps) was investigated.At 1.0 wt% DVB, amphiphilic SNps with hydrophobic patches were formed, further self-assembling into copolymer-SNps clusters occurred.Subsequently, these clusters grow by monomer swelling to finally lead to the formation of core-shell polymer microspheres.Unlike the hydrophilic patchy SNps, at 2.0 and 3.0 wt% DVB, surface-patterned SNps with higher effective hydrophobicity do not self-assemble in the water phase but rather lead to the formation of monoliths.The polymerization mechanisms related to the formation of polymer silica-coated microspheres hybrid-materials, or percolated monoliths with bi-continuous porosity, formed by interfacially jammed emulsion gel (bijels) templates, are discussed herein.

Pt (0.5, 1 and 1.5 wt%) was impregnated by incipient wetness on SBA-15 and corresponding Ga-modified (3, 5, 10 and 20 wt%) composites. Gallium nitrate was incorporated directly during the mesoporous siliceous network synthesis. Materials were characterized by N2 physisorption, X-ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. SBA-15 had surface area greater than 800 m²/g that decreased by Ga incorporation in binary materials. It seemed that tetrahedral gallium was well-incorporated into mesoporous silica walls. Pt dispersion slightly diminished (as to that on SBA-15) by augmenting Ga concentration in composites. Corresponding pore size maxima shifted to lower diameters (as to that of non-impregnated supports) after platinum loading suggesting Pt crystals inside pores of SBA-15 and Ga-modified carriers. Large cubic platinum crystals were observed over all prepared materials probably due to sintering (during calcining at 500 °C) of metallic particles weakly interacting with the carriers surface. After materials annealing (500 °C under static air) metallic platinum was evidenced (by XRD) pointing out to noble metal reduction that could be facilitated by decomposition of organic remains from Si alkoxide used during supports synthesis which presence was ascertained by FTIR.

Alumina-lantana (2.5, 5, 7.5 and 10 wt% La) mixed oxides of suitable texture to be applied as supports of catalysts for hydrodesulfurization of FCC naphtha-range oil-derived distillates were prepared by rare-earth pore-filling impregnation through corresponding nitrate. Co, Mo and P were deposited on binary carriers by one-pot simultaneous impregnation method used during commercial hydrotreating catalysts preparation. Materials were characterized by N2 physisorption, XRD, SEM–EDS, adsorbed CO2 FTIR (basicity measurements), Raman and UV–vis spectroscopies. Sulfided catalysts were studied by chemical composition (EDAX) and HR-TEM. In general, amount and strength of surface basic sites increased with rare-earth content in binary carriers at 5 wt% and higher. Deposited molybdates dispersion augmented with lanthanum content in carriers. However, progressively increasing rare-earth loading on supports was detrimental on gas-phase thiophene HDS (523–563 K, steady-state fixed-bed plug-flow reactor operating at atmospheric pressure). Hardly sulfidable tetrahedral Mo species could be originated by decomposition of heteropolymolybdates originally present in one-pot acidic (pH ~ 1.9) Co–Mo–P solutions by impregnating at basic conditions in pores of La-modified carriers. At isoconversion (~ 10%) rare-earth containing sulfided CoMo catalysts had decreased yield to fully saturated n-butane as to the material supported on pristine alumina.

The adsorption processes have become an additional alternative to hydrotreatment processes of oil-derived middle distillates. The crucial point is the type of adsorbent employed. SBA-15 mesoporous materials were used to adsorb quinoline (Q) and dibenzothiophene (DBT) as N- and S-containing model species, respectively, contained in a model mixture mimicking middle distillates. Q and DBT in dodecane solutions (50-250 ppm and 500 ppm, respectively) were used to that end. In order to improve the adsorption properties, SBA-15 was modified, incorporating zirconium at Si/Zr weight ratios of 5, 16, 60, and 150. At those ratios, Q was adsorbed preferably, whereas DBT was removed only below 10%. To increase the amount of S adsorbed, Zn was incorporated at 2 wt. %. At 250 ppm (sol. concentration) of N, the amount adsorbed of Q and DBT on the material without Zn (Si/Zr = 5) was 1.51 and 0.02 mmolg(ads)(-1), respectively. The results were notably different when Zn was incorporated in adsorbents. In these case, amounts of adsorbed Q and DBT were 2.2 and 1.3 mmolg(ads)(-1), respectively, showing that metal sites are essential to adsorb DBT.

Samples of Mexican light cycle oils were characterized by several techniques. Physical and chemical characteristics are presented. Besides the usual American Standard Test Methods (ASTM) a gas chromatography – mass spectrometry (GC-MS) technique was presented. Based on the GC-MS technique a detailed chemical characterization method was proposed by considering the retention times and sorting out the compounds as hydrocarbon-type derivatives such as benzene, naphthalene, phenanthrene and alkanes derivatives. This procedure is a useful tool for assessing the feasibility and potential of LCO samples as feedstocks for petrochemical or gasoline production. A sample was also distilled in fractions and characterized for the ASTM and GC-MS methods to define the optimum final boiling point for attaining a certain upgrading method.

Alumina-lanthana (La at 1, 3, or 5 wt%) supports were prepared by sol-gel from Al alkoxide sol where La(NO3)3 was added. Annealed (550 °C) xerogels were characterized by N2 physisorption, thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy- energy dispersive spectroscopy (SEM-EDS), CO2-adsorption studied in IR region, Raman and ultraviolet-vis (UV-vis) spectroscopies. The texture of amorphous binary matrices of high La dispersion was adequate to applications in catalysts for middle distillates hydrodesulfurization (HDS). Generally, the amount and strength of surface basic sites increased with La content in solids. Mo (at 2.8 at. nm−2) and Co (at Co/(Co+Mo) = 0.3) were deposited over carriers by one-pot simultaneous impregnation in the presence of PO43− (P2O5/(NiO+MoO3) = 0.2 mass ratio). Calcined (400 °C) Co-Mo-P impregnated precursors had decreased basicity as to that of corresponding carriers, suggesting strong La-deposited species interaction. As La content in carriers increased Mo=O Raman stretching vibrations shifted to lower wave-numbers (949 to 935 cm−1) suggesting octahedral molybdates coordination change to tetrahedral. Although La at the lowest concentration (1 wt%) enhanced dibenzothiophene, HDS (~38% higher as to the Al2O3-supported formulation) desulfurization was significantly diminished at augmented content. Presence of hardly sulfidable tetrahedral Mo originated during impregnation at basic conditions in pores of La-modified carriers seemed to dictate observed behavior. Rare earth content in formulations enhanced selectivity to biphenyl.

Saccharose (SA) was used as organic additive in simultaneously impregnated P-doped NiMo/Al2O3 hydrodesulfurization (HDS) catalysts (Mo, Ni and P at 12, 3, and 1.6 wt%, respectively). One-pot impregnating solutions were prepared by MoO3 digestion (similar to 353 K) in diluted aqueous H3PO4, followed by 2NiCO(3)center dot 3Ni (OH)(24)center dot H2O addition. Saccharose (SA, SA/Ni = 0.5, 1-3) was dissolved in originally emerald-green impregnating solutions which changed to cobalt blue by room-temperature aging (2-4 days, depending on SA concentration) due to Mo-blue formation by partial molybdenum species reduction. After sulfiding of samples impregnated with SA shorter MoS2 slabs of enhanced stacking were observed (by HR-TEM). Ni and Mo dispersion and nickel sulfidability (as determined by XPS) increased with the amount of organic modifier. Enhanced hydrodesulfurization activity in dibenzothiophene HDS was registered for catalyst obtained from Mo-blue precursor as to that of corresponding materials obtained from conventional emerald-green NiMoP impregnating solutions (with or without SA). However, in solids at high saccharose content (SA/Ni = 3) enhanced "NiMoS" phase amount was not reflected in improved activity. Probably, excessive amount of carbonaceous deposits from SA residua decomposition during catalyst activation provoked partially plugged porous network (as determined by N-2 physisorption) in sulfided formulations. That fact seemed to limit accessibility of reactant molecules to surface active sites. Mo-blue precursor obtained through monosaccharides partial reduction seemed to play decisive role in obtaining HDS catalysts of improved properties. Saccharose results a highly soluble, cheap and non-toxic environmentally-friendly additive to produce catalysts of enhanced HDS activity.

The effect of 2,6-bis-(1-hydroxy-1,1-diphenyl-methyl) pyridine (BDPHP) in the preparation of NiMoP/γ-Al2O3 catalysts have been investigated in the hydrodesulfurization (HDS) of straight-run gas oil. The γ-Al2O3 support was modified by surface impregnation of a solution of BDPHP to afford BDPHP/Ni molar ratios (0.5 and 1.0) in the final composition. The highest activity for NiMoP materials was found when the molar ratio of BDPHP/Ni was of 0.5. X-ray diffraction (XRD) results revealed that NiMoP (0.5) showed better dispersion of MoO3 than the NiMoP (1.0). Fourier transform infrared spectroscopy (FT-IR) results indicated that the organic additive interacts with the γ-Al2O3 surface and therefore discards the presence of Mo or Ni complexes. Raman spectroscopy suggested a high Raman ratio for the NiMoP (0.5) sample. The increment of the Mo=O species is related to a major availability of Mo species in the formation of MoS2. The temperature programmed reduction (TPR) results showed that the NiMoP (0.5) displayed moderate metal–support interaction. Likewise, X-ray photoelectron spectroscopy (XPS) exhibited higher sulfurization degree for NiMoP (0.5) compared with NiMoP (1.0). The increment of the MoO3 dispersion, the moderate metal–support interaction, the increase of sulfurization degree and the increment of Mo=O species provoked by the BDPHP incorporation resulted in a higher gas oil HDS activity.

The regular use of light cycle oil (LCO) for diesel fuel production by hydrotreatment (HDT) procedures has been facing difficulties of complying with the currently stricter environmental regulations due to the low quality of this middle distillate with high sulfur, nitrogen, and aromatic contents. An interesting alternative is to obtain valuable petrochemicals from this feedstock. LCO presents a high percentage of diaromatic hydrocarbons (naphthalene derivatives). To facilitate the study of the effect of the experimental conditions, a review regarding the hydrogenation-hydrocracking (HYD-HCK) procedures for obtaining enriched streams containing benzene, toluene, and xylene (BTX) from model mixtures (naphthalene, methylnaphthalenes, and tetralin) is presented. In addition to the economic advantages of using a middle distillate of reduced marketability, this research work opens the door to the development of technologies for obtaining valuable chemicals such as BTX from oil sources. The focus on model mixture studies facilitated the understanding of the involved kinetics and mechanisms and the effect of the experimental conditions on the chemical composition of the products as well.