SBA-15 Catalysts Research Articles

Synergistic effects of Fe2O3 supported on dendritic fibrous SBA-15 for superior photocatalytic degradation of methylene blue

Environmental pollution caused by dye effluent has attracted much attention, and thus developing photocatalysts with superior photodegradation performance is an imperative task. A series of Fe supported on dendritic fibrous SBA-15 (Fe/DFSBA-15) catalysts with various Fe contents were prepared using a microemulsion coupled with ultrasonic-assisted impregnation methods. The findings revealed that the structural stability of DFSBA-15 was unaffected by the amount of Fe loaded. As the Fe loading increased, the size of Fe2O3 nanocrystals increased while the catalysts’ surface area decreased. The bandgap energy of the catalyst decreased with increasing Fe loading and became constant after reaching an optimal Fe loading of 10 wt%. The one-factor-at-a-time study revealed that 10Fe/DFSBA-15 degraded 94.72 % of methylene blue (MB) within 180 min at 1.5 g/L catalyst dosage, pH 8, and 10 mg/L of concentration, owing to Si-O-Fe coordination, modest Fe2O3 crystallite size, homogeneous metal distribution, slower recombination rate, and low bandgap energy. The advantageous features of 10Fe/DFSBA-15 resulted in accelerating the photodegradation rate, where 10Fe/DFSBA-15 is found as the optimal catalyst. The addition of Fe particles to the DFSBA-15 largely improved their photocatalytic activity toward MB degradation, making it a potential candidate for removing pollutants from aqueous solutions.

Adsorption and decomposition of perfluorinated compounds using NiSBA-15 and CuSBA-15 catalysts for greenhouse gas reduction

BackgroundThe persistence of the environmental effects of perfluorinated compounds (PFCs) and fluorinated compounds (FCs) has raised concerns due to their widespread use and long-term impact on ecosystems and human health. MethodsIn this study, we investigated the use of NiSBA-15 and CuSBA-15 catalysts for the adsorption and decomposition of PFCs/FCs (CF₄, SF₆, NF₃, C₃F₈, and C₄F₈) by varying parameters such as weight percentage and contact time. The catalysts were synthesized through an impregnation method with stirring at 300 rpm for 24 h, followed by calcination at 550 °C for 6 h. The catalytic decomposition of NF₃ was conducted using a glass reactor with precise flow rate control and FT-IR monitoring. Variations in acid concentration during synthesis led to structural changes, transitioning from elongated rods to doughnut-like shapes and eventually spherical structures. Impregnation with nickel and copper nitrates successfully modified SBA-15, forming NiSBA-15 and CuSBA-15, as confirmed by HR-TEM images displaying black spots. Catalytic PFC decomposition experiments using unmodified SBA-15 showed limited efficiency, achieving only 15 % NF₃ removal at 500 ppm and 500 °C over 1000 min. Subsequent modification with nickel and copper significantly improved NF₃ removal efficiency. Significant ResultsCuSBA-15 exhibited superior performance compared to NiSBA-15, reaching a remarkable 95 % removal efficiency of NF3. Kinetic analysis using a pseudo-first-order reaction model demonstrated the enhanced catalytic efficiency of the modified SBA-15 catalysts, with increased reaction rate constants (K) for NF3 decomposition. This study reveals the potential of NiSBA-15 and CuSBA-15 catalysts for the adsorption and decomposition of specific PFCs/FCs, offering valuable insights into the underlying mechanisms and practical applications of these catalysts.

Bimetal iron and manganese codoped SBA-16 catalyst: an efficient approach for dye removal through fenton-like reaction

Bimetal iron and manganese codoped SBA-16 catalyst: an efficient approach for dye removal through fenton-like reaction

Direct Hydrothermal Synthesis and Characterization of Zr–Ce-Incorporated SBA-15 Catalysts for the Pyrolysis Reaction of Algal Biomass

In recent years, algae have emerged as a promising feedstock for biofuel production, due to their eco-friendly, sustainable, and renewable nature. Various methods, including chemical, biochemical, and thermochemical processes, are used to convert algal biomass into biofuels. Pyrolysis, a widely recognized thermochemical technique, involves high temperature and pressure to generate biochar and bio-oil from diverse algal sources. Various pyrolytic processes transform algal biomass into biochar and bio-oil, including low pyrolysis, fast pyrolysis, catalytic pyrolysis, microwave-assisted pyrolysis, and hydropyrolysis. These methods are utilized to convert a range of microalgae and cyanobacteria into biochar and bio-oil. In this publication, we will discuss catalytic pyrolysis using mesoporous materials, such as SBA-15. Mesoporous catalysts have earned significant attention for catalytic reactions, due to their high surface area, facilitating the better distribution of impregnated metal. Pyrolysis conducted in the presence of a mesoporous catalyst is viewed more as efficient, compared to reactions occurring within the smaller microporous cavities of traditional zeolites. SBA-15 supports with incorporated Zr and/or Ce were synthesized using the direct hydrothermal synthesis method. The catalyst was characterized using structural and morphological technical analysis and utilized for the pyrolysis reaction of the algal biomass.

Kinetics for the highly selective hybrid and cleaner diesel production by hydro-co-processing of a Jatropha curcas L. oil and gas oil blend using a supported Ni-W/Al-SBA-15 sulfided catalyst

ABSTRACT This work reports the kinetics for the hydro-co-processing of a Jatropha curcas L. oil and gas oil mixture using a sulfided NiO(5.5%)-WO3(25%)/Al(0.05)-SBA-15 catalyst at 360–420°C, 6 MPa of initial H2 pressure, and 4 h of reaction time. It was found that more than 47% of a diesel-like fraction could be obtained due to the HDO of the vegetable oil, and the HDS and HCK of the sulfured and heavier compounds in the gas oil within the mixture. HDO was the most favored reaction, followed by HDS and HCK due to HDO rates were two times higher than those for HDS, demonstrating that oxygen removal was influenced by H2S production during HDS. Accordingly, 96% of the oxygen compounds and 24% of the sulfured compounds were removed during hydro-co-processing. Finally, the intrinsic properties (acidity and metallic character) influenced HCK reactions due to 52.9% of the heavier fraction in the reaction mixture was readily hydroconverted into lighter hydrocarbons. Hence, lighter, cleaner and hybrid fuels can be obtained by hydro-co-processing technologies with the sulfided NiO(5.5%)-WO3(25%)/Al(0.05)-SBA-15 catalyst at reaction temperatures below 400°C to avoid thermal cracking.

Effective amine solvent regeneration over NiO-modified SBA-15 catalysts for energy-saving CO2 capture

Catalytic amine regeneration can decrease the energy required for regeneration; therefore, high economic and energy efficiency can be expected for CO2 capture. These factors necessitate the development of an inexpensive and easily synthesizable catalyst that can exhibit a high desorption efficiency. When selecting a catalyst, its physicochemical properties must be considered, because they markedly affect the chemical reaction between CO2–amine–catalyst. In this study, mesoporous silica SBA-15, particularly, rod-type SBA-15, wrinkled SBA-15 (modified from rod-type SBA-15), and NiO-impregnated rod-type and wrinkled SBA-15 catalysts were investigated in terms of the CO2 desorption rate and heat duty in a CO2–rich 5 M monoethanolamine (MEA) solution at 86 ℃. The physicochemical properties of the catalysts were compared to investigate their effect on the CO2 desorption efficiency. The performance of wrinkled SBA-15 impregnated with 10 wt% NiO in a CO2–rich MEA solution was optimal, exhibiting a 12 % higher CO2 desorption rate and 19.9 % lower heat duty than the MEA solution without a catalyst. Furthermore, the stability and reproducibility of the catalysts were confirmed through repeated experiments under identical conditions. Based on the experimental results and analysis, a plausible desorption mechanism for CO2–MEA–catalyst was proposed. It is expected that the regeneration heat duty during the CO2 regeneration can be effectively reduced by a catalyst, eventually applied to the CO2 capture.

Ni supported on Ti-doped SBA-15 catalyst for the selective hydrodeoxygenation conversion of lignin derivatives

The development of cost-effective and efficient catalysts plays a critical role in the selective hydrodeoxygenation of lignin derivatives for lignin valorization. Herein, we reported “metal-acid” bifunctional catalysts (Ni/Ti-SBA-15) consist of Ni nanoparticles highly dispersed on Ti doped SBA-15, which achieved 100% vanillin conversion and 96.46% selectivity of 2-methoxy-4-methylphenol (MMP) under mild conditions. Characterizations were employed to reveal the morphology and physicochemical properties of the catalysts. The results indicated that doping of Ti species not only increased the number of acidic sites but also promoted the high dispersion of Ni nanoparticles on the support. This research provides a novel concept for the synthesis of cost-effective and efficient catalysts, which contributes to the environmentally friendly and economical conversion of biomass derivatives.

Modulating selectivity in CO2 Methanation through Rhodium catalysts supported on Zirconia-Chemically grafted SBA-15

This study presents the impact of ZrO2 incorporation on Rh-supported SBA-15 catalysts for CO2 hydrogenation. ZrO2 was chemically grafted onto the SBA-15 surface, varying concentrations of ZrO2 from 5 to 20 wt.%. The ZrO2-free catalyst favored CO production, leaning towards the reverse water gas shift reaction. The addition of ZrO2 notably enhanced catalytic activity and led to a significant shift in selectivity towards methane production. The selectivity modulation is linked with the modified surface of SBA-15, covered with a ZrO2 phase. The FTIR characterization under reaction conditions evidenced Rh-carbonyls formation in all samples. However, in catalysts materials with ZrO2, formate species are also formed, probably promoted by the Zr-OH groups. A linear relation between formate species and the CH4 selectivity suggests that the methane formation could be associated with the hydrogenation of formate species, while the desorption of carbonyls on Rh can explain the CO generation.

Synergistic Interaction between Ruthenium Catalysts and Grafted Niobium on SBA-15 for 2,5-Furandicarboxylic Acid Production Using 5-Hydroxymethylfurfural.

This study entailed the synthesis of Ru nanocatalyst decorated on Nb-grafted SBA-15. A Nb-grafted SBA-15 support with varying Nb contents was utilized as a support for the Ru nanoparticles. The effect of Nb grafting on the immobilized Ru nanoparticle catalyst was systematically investigated, and its catalytic performance in the synthesis of furandicarboxylic acid using 5-hydroxymethylfurfural under base-free reaction conditions was evaluated. The results indicate the increased productivity of the Ru@Nb-grafted SBA-15 catalyst with a yield exceeding 95%, representing a significant advancement in catalysis. This study also affords insights into the complex relationship between the catalytic activity and selectivity and its unique surface attributes. Moreover, acidic sites were created, and the electron density within the active sites was modulated by monomeric Nb oxide species on the SBA-15. Additionally, the role of high-electron-density Ru atoms in facilitating the efficient adsorption and activation of the reactant, resulting in enhanced catalytic efficacy, was highlighted.

Optimizing CO2 Hydrogenation to DME through Tailored Interfacial Interactions: Weakening Synergy in CuZnZr and Al-Modified SBA-15 Catalysts

Optimizing CO₂ Hydrogenation to DME through Tailored Interfacial Interactions: Weakening Synergy in CuZnZr and Al-Modified SBA-15 Catalysts

Relationship between the Acid-base Properties of Nitrogen-modified ZnO-ZrO2/SBA-15 Catalysts and Their Catalytic Performance in the Synthesis of 1,3-Butadiene from Ethanol

Relationship between the Acid-base Properties of Nitrogen-modified ZnO-ZrO₂/SBA-15 Catalysts and Their Catalytic Performance in the Synthesis of 1,3-Butadiene from Ethanol

Optimizing 5-hydroxymethylfurfural production from biomass carbohydrates: ionic liquid-catalyzed pathways in deep eutectic solvents under sonication and thermal conditions

The synthesis of ionic liquid (IL)-based mesopore SBA-16 catalyst for the conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural (5-HMF) in the presence of 15 deep eutectic solvents (DESs) under sonication and thermal conditions.

Ni-Fe bimetallic catalysts with high dispersion supported by SBA-15 evaluated for the selective oxidation of benzyl alcohol to benzaldehyde.

A wetness impregnation method was used to impregnate the substrate with a substantial quantity of oleic acid together with a metal precursor, leading to significantly dispersed Ni-Fe bimetallic catalysts based on mesoporous SBA-15. Using a wide variety of characterization methods, such as XRD, BET, and TEM Analysis, the physiochemical properties of the catalyst were determined. The addition of the metal does not have any effect on the structural characteristics of the SBA-15 catalyst, as validated by transmission electron microscopy (TEM), which shows that the prepared SBA-15 supported catalyst has a hexagonal mesoporous structure. The catalytic capabilities of the Ni-Fe-SBA-15 catalysts were evaluated in the conversion of BzOH using tert-butyl hydroperoxide (TBHP) as an oxidant and acetonitrile as a solvent. The Ni/Fe-SBA-15 (NFS-15) catalytic composition is the best of the developed catalysts, with a maximum conversion of 98% and a selectivity of 99%. In-depth investigations were conducted into the molar ratio of TBHP to BzOH, the dosage of the catalyst, the reaction rate, temperature, and solvent. The recycling investigations indicate that the synthesized Ni/Fe-SBA-15 (NFS-15) catalyst seems to be more durable up to seven successive cycles.

Synthesis and evaluation of novel copper hydroxide-loaded SBA-15 as inhibitors for an oilfield carbonate scale control: an experiment and a model study

Abstract The oil and gas industry faces significant challenges in scaling, leading to financial losses and production decline. This study aims to synthesize solid-scale inhibitors using copper hydroxide-loaded SBA-15 catalysts for the scale removal. The catalysts were synthesized using a simple impregnation method, and characterized using various tests. To evaluate the scale inhibition efficiency, static scale inhibition tests are conducted, measuring the effectiveness of the synthesized inhibitors in preventing scale formation. The results show potential applications for copper hydroxide-loaded SBA-15 solid-scale inhibitors in the oil and gas industry. The inhibitor's efficiency increases under alkaline conditions, while its efficacy decreases with rising pH. At an optimal dosage of 7.5 ppm and temperature of 55 °C, the inhibitor achieves an impressive 99% inhibition efficiency on calcium carbonate, indicating excellent inhibitory performance. This material holds promise for more efficient and cost-effective scaling inhibition solutions across various industrial processes.

Boosting the Hydrodeoxygenation Activity and Selectivity of Ni/(M)-SBA-15 Catalysts by Chemical Alteration of the Support.

The influence of the acid sites in the hydrodeoxygenation of anisole performed over Ni catalysts supported on SBA-15 modified with metal oxides (Ni/M-SBA-15, M = Ti, Zr, Al, or Nb) was demonstrated. Catalysts were characterized by SEM-EDX, nitrogen physisorption, XRD, UV-visible DRS, TPR, TPD of ammonia, IR-Py, O2 chemisorption, and high-resolution transmission electron microscopy. The mesoporous structure and the hexagonal arrangement of the supports were maintained in the catalysts. Ni catalysts supported on modified M-SBA-15 exhibited a higher metal-support interaction, an increase in the acidity and, as a consequence, improved selectivity to cyclohexane. The deoxygenation reaction rate constants increased as Ni/SBA-15 < Ni/Ti-SBA-15 < Ni/Nb-SBA-15 < Ni/Zr-SBA-15 < Ni/Al-SBA-15, which is attributed to the increase in the amount and strength of acid sites, especially of the Brønsted ones, which promotes the cleavage of the C-O bond. It is also important to keep the metal/acid sites together to obtain high activity and selectivity to hydrodeoxygenated products.

Elucidation on supporting effect of WO3 over MCF-Si and SBA-15 catalysts toward ethanol dehydration

BackgroundThe alternative conversion of ethanol into valuable products, such as ethylene, through catalytic ethanol dehydration becomes highly appealing due to the surplus of ethanol. This research aims to investigate the catalytic activity of WO3 on SBA-15 and mesocellular form silica (MCF-Si), which have been prepared using different methods and utilized as catalysts in ethanol dehydration. MethodsWO3 was impregnated on the SBA-15 and MCF-Si supports using two different methods, including incipient wetness (IW) and wetness impregnation (W). All catalysts were tested in the vapor phase of ethanol dehydration at reaction temperatures ranging from 200 to 400 °C and were characterized by powerful techniques. Significant findingsThe findings revealed that the three-dimensional mesocellular foam structure of MCF-Si and the incipient wetness impregnation of WO3 are the keys to obtaining a highly dispersed WO3 catalyst with suitable acid properties. Additionally, the high Lewis to Bronsted (L/B) ratio of tungsten on silica is crucial for the catalytic dehydration of ethanol to ethylene. Among all catalysts, the WO3/MCF-Si (IW) exhibited the highest ethylene yield (98.3%), having an ethanol conversion of 99.6% and an ethylene selectivity of 98.7% at 400 ºC.

Ni-Based SBA-15 Catalysts Modified with CeMnOx for CO2 Valorization via Dry Reforming of Methane: Effect of Composition on Modulating Activity and H2/CO Ratio.

Dry reforming of methane with ratio CH4/CO2 = 1 is studied using supported Ni catalysts on SBA-15 modified by CeMnOx mixed oxides with different Ce/Mn ratios (0.25, 1 and 9). The obtained samples are characterized by wide-angle XRD, SAXS, N2 sorption, TPR-H2, TEM, UV-vis and Raman spectroscopies. The SBA-15 modification with CeMnOx decreases the sizes of NiO nanoparticles and enhances the NiO-support interaction. When Ce/Mn = 9, the NiO forms small particles on the surface of large CeO2 particles and/or interacts with CeO2, forming mixed phases. The best catalytic performance (at 650 °C, CH4 and CO2 conversions are 51 and 69%, respectively) is achieved over the Ni/CeMnOx/SBA-15 (9:1) catalyst. The peculiar CeMnOx composition (Ce/Mn = 9) also improves the catalyst stability: In a 24 h stability test, the CH4 conversion decreases by 18 rel.% as compared to a 30 rel.% decrease for unmodified catalyst. The enhanced catalytic stability of Ni/CeMnOx/SBA-15 (9:1) is attributed to the high concentration of reactive peroxo (O-) and superoxo (O2-) species that significantly lower the amount of coke in comparison with Ni-SBA-15 unmodified catalyst (weight loss of 2.7% vs. 42.2%). Ni-SBA-15 modified with equimolar Ce/Mn ratio or Mn excess is less performing. Ni/CeMnOx/SBA-15 (1:4) with the highest content of manganese shows the minimum conversions of reagents in the entire temperature range (X(CO2) = 4-36%, X(CH4) = 8-58%). This finding is possibly attributed to the presence of manganese oxide, which decorates the Ni particles due to its redistribution at the preparation stage.

Dry Reforming of Methane over Ni-Supported SBA-15 Prepared with Physical Mixing Method by Complexing with Citric Acid

Ni-supported SBA-15 catalysts were prepared by physical mixing of Ni(NO3)2·6H2O and SBA-15 (Ni/SBA-15-M) and in the presence of citric acid as the complexing agent (Ni/SBA-15-M-C). Moreover, an Ni-supported SBA-15 catalyst was also prepared by the conventional incipient impregnation method (Ni/SBA-15-I). All the catalysts were systematically evaluated for carbon dioxide reforming of methane (CDR) at CO2/CH4 = 1.0, gas hourly space velocity of 60,000 mL·g−1·h−1, and reaction temperature of 700 °C. The characterization results show that the Ni particle size of Ni/SBA-15-M-C is significantly smaller than that of Ni/SBA-15-M due to the coordination effect of citric acid and Ni2+. Consequently, the Ni/SBA-15-M-C exhibits superior anti-coking and anti-sintering during the CDR-operated period because of the higher Ni dispersion and stronger Ni–support interaction. Compared to the Ni/SBA-15-I, the physical mixing of nickel salt and mesoporous material for preparing of Ni-based catalyst is easy to operate, although the crystal size and catalytic performance of Ni/SBA-15-C are very similar to that of Ni/SBA-15-M-I. Thus, the efficient and easily controlled catalyst structure makes the physical mixing strategy very promising for preparing highly active and stable CDR catalysts.

Production of a high molecular weight jet-fuel precursor from biomass derived furfural and 2-methylfuran using propyl sulfonic SBA-15 catalysts

An effective catalyst for the production of branched chain fuel precursors with 15 carbon atoms (C15) from low carbon number, biomass-derived molecules is reported in this work. It shows that SBA-15 silica with the incorporation of sulfonic groups (S15) is highly active and selective for C-C coupling at low temperature, without solvent and under simple reaction conditions, giving a C15 condensation product with high selectivity, greater than 95 %, via hydroxyalkylation/alkylation (HAA) of 2-methylfuran (2-MF) with furfural (FAL). As water was determined to have a great negative influence on the stability of these catalysts, synthesis modifications and various post-synthesis treatments were tested to improve yield of C15. As a result, it was possible to improve up to 12 % the efficiency of the reaction by incorporating hydrophobic groups in the synthesis of sulfonic SBA-15 by co-condensation. This catalyst can be recovered and recycled, preserving its stability over multiple reaction cycles.

Reduction of Typical Diesel NOx Emissions by SCR-NH3 Using Metal-Exchanged Natural Zeolite and SBA-15 Catalysts

In this work, the catalytic performance of clinoptilolite (CLIN) and SBA-15 catalysts, doped with Fe and Cu, was evaluated in the selective catalytic reduction of NO using NH3 as a reducing agent (SCR-NH3). Both Cu-CLIN and Fe-CLIN were obtained by ion-exchange using natural clinoptilolite zeolite originating from the Hrabovec deposit (northeast Slovakia region). Cu-SBA-15 and Fe-SBA-15 were prepared by impregnation into SBA-15 mesoporous synthesized silica. Standard catalytic activity tests were carried out on a bench-scale laboratory apparatus using a reaction mixture of a standard test. GHSV of 48,000 h−1 was adopted based on the space velocity of a real NH3-SCR catalyst for diesel vehicles (100–550 °C). All Cu-doped samples showed better NO conversion values than Fe-doped samples. Clinoptilolite catalysts were more active than those based on SBA-15. Maximum NO conversions of about 96% were observed for Cu-CLIN and Fe-CLIN at 350–400 °C, respectively. Moreover, Fe-CLIN also showed higher stability in the presence of SO2 and water steam at 350 °C. These results demonstrate the potential of metal-doped natural clinoptilolite to be used as cost-effective catalysts applied to the abatement of NOx emissions generated in automotive combustion processes.