Mesoporous Research Articles

Synthesis and characterization of mesoporous caged silica for efficient adsorption of methylene blue from aqueous solution

Addressing the challenge of removing dyes from textile industry wastewater is crucial for wastewater treatment. Adsorption, utilizing suitable materials, emerges as a promising solution. This work introduces caged silica as an effective adsorption material for wastewater treatment in the textile industry. The proposed caged silica was synthesized via the hard template synthesis method, commonly used in various applications such as catalysts and wastewater treatment. Caged silica exhibited an amorphous structure with notable BET surface area (448m2/g), pore volume (0.325cm3/g), and average pore size (2.4nm), confirmed through detailed characterization. Evaluation of its adsorption capacity for methylene blue (MB) revealed an impressive removal efficiency of approximately 95% within the initial 20 min. The adsorption process followed the pseudo-second-order model and adhered more closely to the Freundlich isotherm model than the Langmuir model. Additionally, the study investigates the effects of pH, percent removal efficiency, cyclic stability, and initial MB concentration on the adsorption procedure. Consequently, the synthesized caged silica stands out as a promising mesoporous material for efficiently removing MB from aqueous solutions, offering practical application potential in wastewater treatment.

A unified description of ion exchange and complete adsorption isotherms, including cluster growth and cavity filling

In the context of micro- and mesoporous materials, the interpretation of ion exchange and gas adsorption isotherms rarely covers the full information content of the experimental data. Based on our earlier work regarding the role of entropy in multiple equilibria, we have revisited cation exchange data of zeolite A in more detail and addressed the analysis of Ar and N2 adsorption isotherms of nonporous, microporous and mesoporous silicates. The previously reported analysis is thereby extended and improved. The theory is presented in a unified and compact manner through rigorous application of the concept of fractional amount, including particle distribution, cluster growth, and cavity filling. A result is that the structure of mesoporous silica MCM-41 can be described as consisting of the main channel and two types of cavities, which can be interpreted as surface roughness. In a further step, the information delivered by the inflection points in type I, II and IV gas adsorption isotherms is considered. The adsorption of simple gases begins with the formation of a monolayer on the pristine surface. The inflection point thereby represents the start of a new process, indicating that the adsorption isotherms must be understood as the signature of several sequential chemical equilibrium steps. Information can be extracted by inspecting this signature more closely. The results demonstrate the ability of the reported procedure to elicit additional insight including structural features from experimental equilibrium isotherm data.

A combined experimental and simulations assessment of CO2 capture and CO2/H2 separation performance of aminosilane-grafted MCM-41 and pore-expanded MCM-41

Amine-functionalized mesoporous silica materials have attracted considerable attention as robust adsorbents for large-scale CO2 capture and direct air capture (DAC). Amine grafting increases selective affinity at low pressures, yet also often reduces the adsorbent's pore volume and surface area, affecting the kinetics and capacity upon CO2 adsorption. MCM-41 and pore-expanded MCM-41 (PE-MCM-41) were developed here, functionalized using 3-aminopropyl triethoxy silane (APTES), and comparably evaluated for their carbon capture performance at different conditions by a combinational experimental, equilibrium and kinetic modelling, and molecular simulations approach. In specific, CO2 adsorption capacity, CO2/N2 selectivity, CO2 adsorption at humid conditions, heat of adsorption, and regeneration/cyclability were assessed, coupled to molecular simulation insights on the physisorption and chemisorption contribution to the overall adsorption uptake. Indicatively, a capacity value of 3.07 and 2.44 mmol/g was obtained for APTES-PE-MCM-41, and 2.27 and 1.89 mmol/g for APTES-MCM-41, under wet and dry conditions, respectively. The CO2 selective adsorption from H2 rich gas streams was also examined over APTES-MCM-41 in order to assess the potential application in H2 stream purification process. The latter is of high significance in order to use hydrogen as fuel e.g. in anion exchange membrane fuel cells for power production since the presence of CO2 in the feed composition is considered a major drawback in their commercialization.

Polyoxometalate based ionic liquids reinforced on magnetic nanoparticles: A sustainable solution for microplastics and heavy metal ions elimination from water

To purify water from contaminents is essential for life on universe. Here, in this manuscript we introduces an innovative approach to overcome the intricate challenge of eliminating heavy metal ions and microplastics from water. We designed a mesoporous composite materials by synergistically integrating polyoxometalates (POMs) based ionic liquids with silica coated magnetic nanoparticles. The synthesis process initiates with the utilization of highly reduced molybdenum aggregates in polyoxometalate-ionic liquids, reinforced onto magnetic nanoparticles (POM–IL–MNPs). Crafted composites, including Q8[Mo64Ni8La6]@SiO2@Fe3O4, Q10[Mo64Ni8La6]@SiO2@Fe3O4, Q8[Mo176/Mo248]@SiO2@Fe3O4, and Q10[Mo176/Mo248]@SiO2@Fe3O4, are meticulously designed by substituting POM counter cations with long-chain alkyl-based quaternary ammonium salts. The ionic liquids and composites exhibit remarkable hydrophobicity and thermal stability due to large anions and long-chain organic counter cations. Comprehensive characterization, including FT–IR, UV–vis spectroscopy, TGA, DSC, CV, rheological study, elemental analysis, and ICP-AES, ensures a thorough investigation. Additional analyses, such as Powder X-ray diffraction (PXRD), SEM, EDX, DLS, N2 adsorption, and VSM, reveal amorphous crystallinity, distinctive surface morphology, and substantial specific surface area. Core shell structure of POM-IL-MNPs was determined by Transmision electron microscope (TEM), ICP-AES analysis demonstrates metal ion removal efficiencies from 87.35% to 99.98%, with DLS confirming 100% efficiency in PVC beads elimination. This research not only advances water decontamination but also provides valuable insights into designing and characterizing novel materials with promising environmental applications.

Local grafting heterogeneities control water intrusion and extrusion in nanopores

Hydrophobic nanoporous materials can only be intruded by water forcibly, typically increasing pressure. For some materials, water extrudes when the pressure is lowered again. Controlling intrusion/extrusion hysteresis is central in technological applications, including energy materials, high performance liquid chromatography, and liquid porosimetry, but its molecular determinants are still elusive. Here, we consider water intrusion/extrusion in mesoporous materials grafted with hydrophobic chains, showing that intrusion/extrusion is ruled by microscopic heterogeneities in the grafting. For example, intrusion/extrusion pressures can vary more than 60 MPa depending on the chain length and grafting density. Coarse-grained molecular dynamics simulations reveal that local changes in radius and contact angle produced by grafting heterogeneities can pin the water interface during intrusion or facilitate vapor bubble nucleation in extrusion. These microscopic insights can directly impact the design of energy materials and chromatography columns, as well as the interpretation of porosimetry results.

Novel highly utilized PdNi bimetallic-loaded N-doped carbon catalysts prepared from MOF for Suzuki coupling reaction and hydro reduction of nitroaromatics

The usage of palladium-based catalysts in numerous chemical reactions has been increased significantly; in particular, the synthesis of heterogeneous catalysts by attaching palladium atoms to carriers has expanded rapidly. Therefore, the selection of nitrogen-doped carbon materials for carriers has become a popular research subject. In this study, Ni-Ni PMOF was first created, then Ni nanoparticles (NPs) modified nitrogen-doped mesoporous carbon materials were synthesized through pyrolysis. Subsequently, Pd atoms were successfully deposited onto the surface of Ni NPs as Pd2+ is capable of being reduced by metal Ni. The structure of the prepared carriers was verified by FT-IR, XRD, SEM, TEM, XPS and other characterizations, and was found to have a fluffy and porous structure that increases the number of active sites of PdNi NPs. This material was found to be effective in catalyzing the Suzuki coupling reaction (TOF = 1019 h) and the reduction reaction of p-nitrophenol (Kapp = 4.34 × 10−2 s−1), and its catalytic activity remained stable even after 10 uses, showing good recoverability and recyclability. This study thus provides a novel approach for the preparation of N-doped porous carbon materials, which can enable green chemistry by making efficient and full use of precious metals.

Isotherm, Kinetics, and Adsorption Mechanism Studies of Coal Gasification Coarse Slag as Highly Efficient Phosphate Adsorbents

This study investigates the efficacy of a novel low-cost phosphate adsorbent, denoted as SH-CGCS, derived from coal gasification coarse slag (CGCS) via an alkali activation method. SH-CGCS is a mesoporous material with a specific surface area (64 m2/g) approximately six times larger than CGCS (11 m2/g), which enhances its adsorption capacity compared with CGCS. Furthermore, SH-CGCS achieves a phosphate adsorption capacity of 38.5 mg/g in strongly acidic water (pH 3) and demonstrates robust acid resistance, which makes it particularly effective for phosphate removal from acidic wastewater. Results from coexisting anion experiments affirm the good adsorption selectivity of SH-CGCS for phosphate. Moreover, SH-CGCS exhibits proficiency in treating water containing low phosphate concentrations under flowing conditions. The maximum phosphate adsorption capacity of SH-CGCS calculated using the Langmuir model is 23.92 mg/g, surpassing that of other reported adsorbents. Importantly, saturated SH-CGCS can be regenerated and reused, which contributes to its practical applicability. The adsorption mechanisms of SH-CGCS for phosphate involve ligand exchange, inner-sphere complexation, surface precipitation, and electrostatic adsorption. Thus, this study not only enhances the overall utility of CGCS but also presents a simple and efficient method for removing phosphate. Our findings indicate that SH-CGCS holds considerable potential as a phosphate adsorbent, offering a promising solution for wastewater treatment.

Heterogenization of [Ru(bpy)3]Cl2 on Ordered Mesoporous Silica Materials for Photocatalytic Applications

AbstractHerein, the preparation and characterization of three Ru-based heterogeneous photocatalysts supported on ordered mesoporous silica materials are reported. The photocatalytic activity of these catalysts was evaluated through oxidation, reduction, cycloaddition, and carboxylation reactions and their efficiencies are comparable to the parent [Ru(bpy)3]Cl2 under homogeneous conditions. These photocatalysts are efficiently recovered even after five reaction cycles offering new opportunities in sustainable chemistry.

Efficient removal of Pb (II) ions from aqueous solution by the Moringa oleifera synthesized magnetic ZnFe2O4 spinel nanoparticles

Water-based Pb(II)ion removal was tested on Moringa oleifera modified ZnFe2O4 nanoparticles. For the strong crystal plane, XRD analysis predicts high crystallinity and 18 nm average crystallite sizes. Tetrahedral and octahedral spikes oscillate at 650 and 482 cm−1, metal ions like Zn-O and Fe-O resonate at 400–600 cm−1. Porosity particles and complicated integration linkages with hydroxyl groups from distinct fatty acid sequences characterise omega-3 and zinc ion nanoparticles. HRTEM images revealed spherical ZnFe2O4 nanoparticles with an average diameter of 8–12 nm and interplanar spacing and lattice fringes matching the tetragonal phase's (311) crystal plane. Due to interparticle gaps, N2 equilibrium temperatures at 77.5 K produced mesoporous material with 120.6 m2 g−1 BET specific surface area and 15.6 nm pore width. Spinel ZnFe2O4 demonstrated photocatalytic activity in daylight with prolonged UV-to-visible photo absorption. Prepared nanoparticles exhibited ferromagnetic functionality, a saturation magnetic field of 10 emu/g, a permanence of 2 emu/g, and a forcefulness of 100 Oersted has, which is less than the significant value of 72 emu/g. Lead elimination kinetics show that PSO kinetics better capture adsorption kinetics than PFO kinetics. Rate diffusion-driven surface features may potentially explain Pb(II) adsorption kinetics. pH 6.2 is optimal for Pb(II) removal. Adsorption process seems endothermic and impulsive. Monolayer adsorption over a consistent region may have deposited Pb(II) on ZnFe2O4. Langmuir method found ZnFe2O4 maximum adsorption capacity of 142.2 lead (mg)/adsorbent (g) and it adsorbs lead (II) ions similarly to other adsorption agents, perhaps due to its large effective surface area.

Tuning Textural Properties by Changing the Morphology of SBA-15 Mesoporous Materials.

Changing the morphology is an excellent option for altering the textural parameters of SBA-15 materials. This study provides a guide on how the properties of mesoporous structures behave according to their morphology and their contribution to thermal stability. The objective of this work was to synthesize different morphologies (spherical, hexagonal prisms, rice-like grains, rods, and fibers) of SBA-15 materials and evaluate the existing textural changes. The materials were synthesized by varying the temperature of the synthesis gel from 25 °C to 55 °C, with stirring at 300 or 500 rpm. The results of X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption and desorption, and scanning electron microscopy were evaluated. Thermal stability tests were also conducted in an inert atmosphere. The materials were successfully synthesized, and it was observed that they all exhibited different characteristics, such as their ordering, interplanar distance, mesoporous parameter, specific surface area, micropore and mesopore volumes, external mesoporous area, and wall thickness. They also presented different thermal stabilities. The rice grain morphology had the highest specific surface area (908.8 cm2/g) and the best thermal stability, while the rod morphology had the best pore diameter (7.7 nm) and microporous volume (0.078 cm3/g).

Alcohol formaldehyde resin solid acid catalytic conversion of biomass into furan compounds

The conversion of waste lignocellulosic biomass into biomass platform chemicals is very promising. In this work, a novel resin-based solid acid catalyst was obtained by condensation of furfuryl alcohol with furfural, and mild calcination and sulfonation process. Then it was used to convert sugars and biomass to obtain furan compounds. Results showed that the solid acid with a furfural to furfuryl alcohol molar ratio of 3:1 is an irregular mesoporous material, with a specific surface area of 134.18 m2/g and an acid content of 2.723 mmol/g, which is extremely stable below 200 °C. 82.2 % (from fructose), 15.8 % (from glucose), 10.0 % (from cellobiose) yields of 5-HMF and 35.5 % (from xylose) yield of furfural could be obtained at 160 °C for 2 h. It can be reused more than 5 times and can restore the best catalytic effect after re-sulfonation. Notably, in the catalytic conversion of rice husk, rice straw, camphor tree branch and leaves under typical reaction conditions, 5-HMF and furfural was in yields of 9.4–24.5 % and 20.3–47.9 %, respectively. Moreover, a 10 % water dropwise to solvent can effectively promote the catalytic conversion of biomass, while there is a significant inhibitory effect after it exceeds 20 %.

Nanoscale structural transformations in LaFeO3 oxygen carriers for enhanced reactivity in chemical looping combustion

The push for decarbonization necessitates the development of clean and efficient energy conversion technologies. Among these, the chemical looping platform has emerged as a promising approach, albeit with challenges such as high operating temperatures. This necessitates the design of high-performance chemical looping carriers. In this study, we explore the potential of nanosized oxygen carriers, noted for their high reactivity, for the chemical looping combustion of methane (CH4). LaFeO3, a widely investigated perovskite-type mixed metal oxide known for its effectiveness as an oxygen carrier, is examined. Nanosized LaFeO3 is synthesized by embedding LaFeO3 onto mesoporous silica matrix (LFO-SBA15), and its reactivity is benchmarked against bulk-scale LaFeO3 supported on SiO2 (LFO-SiO2). The nanosized carrier demonstrates a ∼ 1000% improvement in reactivity compared to the bulk carrier. This enhancement is attributed to the formation of a highly reactive cubic phase of LaFeO3 at the nanoscale, in contrast to the orthorhombic phase present in bulk-scale LaFeO3. This finding is supported by density functional theory calculations, which reveal that the cubic phase of LaFeO3 facilitates the formation of oxygen vacancies and lowers the energy barrier for CH4 dissociation. This work highlights the potential of nanosized LaFeO3 for the chemical looping combustion of CH4, providing valuable guidance for the rational design and development of high-performance chemical looping carriers.

Progress in Core-Shell Magnetic Mesoporous Materials for Enriching Post-Translationally Modified Peptides.

Endogenous peptides, particularly those with post-translational modifications, are increasingly being studied as biomarkers for diagnosing various diseases. However, they are weakly ionizable, have a low abundance in biological samples, and may be interfered with by high levels of proteins, peptides, and other macromolecular impurities, resulting in a high limit of detection and insufficient amounts of post-translationally modified peptides in real biological samples to be examined. Therefore, separation and enrichment are necessary before analyzing these biomarkers using mass spectrometry. Mesoporous materials have regular adjustable pores that can eliminate large proteins and impurities, and their large specific surface area can bind more target peptides, but this may result in the partial loss or destruction of target peptides during centrifugal separation. On the other hand, magnetic mesoporous materials can be used to separate the target using an external magnetic field, which improves the separation efficiency and yield. Core-shell magnetic mesoporous materials are widely utilized for peptide separation and enrichment due to their biocompatibility, efficient enrichment capability, and excellent recoverability. This paper provides a review of the latest progress in core-shell magnetic mesoporous materials for enriching glycopeptides and phosphopeptides and compares their enrichment performance with different types of functionalization methods.

Exploring nitrogen doped mesoporous carbon spheres for superior microwave absorption

Mesoporous carbon materials hold significant promise for usage in microwave absorption due to their wide and unique advantages stemming from their mesoporous structure. This study synthesizes N-doped mesoporous carbon spheres (NMCs) by carbonizing mesoporous silica nanospheres (MSN). By controlling the annealing temperature, the resulting NMCs exhibit a significant increase in pore size. The exceptional microwave absorption capability of multifunctional carbon with a mesoporous structure result from its appropriate composition. The minimum reflection loss (RL) can reach −58.04 dB with a thickness of 3.3 mm, and the corresponding effective absorption bandwidth (EAB) reaches up to 8.19 GHz, outperforming the many previously documented microwave absorbing materials. The material's practical application potential was evaluated using computer simulation technology (CST), resulting in a simulated RCS value of 32.88 dBm2.The microwave absorption process of this material has been extensively studied and thoroughly described. Our study offers valuable guidance for developing and producing efficient microwave absorbers doped with nitrogen and possessing a unique mesoporous structure.

MRI and PFG NMR studies of percolation effects in advanced melting during a cryoporometry characterisation of disordered mesoporous alumina

Cryoporometry (or thermoporometry) offers a way of pore structural characterisation for mesoporous materials that often needs little sample preparation, is relatively quick, and is statistically-representative for macroscopic samples. While it is well-known that freezing is controlled by pore-blocking, and is thus an invasion percolation process, the percolative nature of pore-to-pore co-operative advanced melting effects has been much less studied. In this work, PFG NMR studies, of diffusivity within the molten phase, have shown that the early melting process follows the scaling law, expected from percolation theory, below the percolation threshold. The percolation threshold thereby obtained was that for a 3D isotropic Poisson polyhedral lattice, consistent with the observation of patchwise macroscopic heterogeneities in the spatial distribution of local average pore size seen in MR relaxation time-weighted images. MRI has shown that once advanced melting effects kicked-in, around the percolation threshold, they occurred to different degrees in different slices along the length of the extrudate pellet. The macroscopic banding in pore-blocking, during freezing, and advanced melting effects, along the axis of the extrudate was consistent with anisotropic diffusional properties observed with MRI. Hence, it has been shown how the pore-pore co-operative effects can be utilised to improve structural characterisation of mesoporous solids.

Antibacterial Activity and CO<sub>2</sub> Capture by Cerium-Copper Mixed Oxides Prepared Using a Co-precipitation Method

Indoor air pollution is comprised of fine particles, bacteria, fungi, and hydrocarbons. Acceptable indoor air quality is maintained using several layers of air filters. Alternative materials with the capacity to remove CO2 from indoor air with antibacterial efficacy need to be further investigated. Mixed oxides of Ce1.0-xCuxO (x = 0.0, 0.1, 0.5, 0.9, 1.0) were synthesized using a co-precipitation method. Characterization studies revealed that single oxides of Ce1.0O and Cu1.0O were of cubic fluorite and monoclinic crystal structures, respectively. Results also show that Ce0.1Cu0.9O and Ce0.5Cu0.5O were composites. All samples were classified as mesoporous materials with a type IV isotherm, and the main functional group was identified as Ce–O–Cu. The surface area of Ce0.5Cu0.5O was 17.63 m2/g. The highest CO2 adsorption capacity was 5.72 cm3/g for Ce0.5Cu0.5O. Moreover, the greatest antibacterial activity against B. subtilis (12.22 mm inhibition zone) and P. aeruginosa (7.34 mm inhibition zone) was observed for Ce0.5Cu0.5O at a 30 mg/L concentration. The synthesis of mixed Ce1.0-xCuxO oxides along with their satisfactory antibacterial performance and CO2 adsorption capacity, indicate its potential use as an alternative material for inclusion in indoor air filters.

Impact of trivalent Yttrium on the structural and optical properties of CaAl2O4: New frontier in supercapacitor positive electrode

In this work, trivalent Yttrium doped calcium aluminate (CaAl2O4:x% Y3+) were synthesized for the first time. Through Photoluminescence (PL) spectroscopy and Commission Internationale de l’Eclairage (CIE), CaAl2O4:0.1 % Y3+ has demonstrated to be a potential high emitting phosphor material amongst other high concentration Y3+ doped samples, emitting a vibrant blue – pink hue where others are emitting a transiting hue from blue to green within a white vertex region. FTIR and UV–Vis have confirmed the prepared material and the presence of Y dopant. The SEM showed insignificant morphological change and the presence of pores, which were quantified using BJH and DFT methods to be micro – and meso–pores. Moreover, CaAl2O4 is also being reported as a positive electrode in supercapacitors for the first time. The analysis shows that it has superior performance within 1 M KOH electrolyte, with a specific capacity of 47.71 mA h g−1 at 1 A g−1 and a maximum power of 39.68 kW kg−1. Trasatti's method showed a surface (138 Fg-1) and diffusion (695 Fg-1) contribution ratio of 17:83 (%) of the total stored energy. It has a capacity retention and columbic efficiency of 100 % at the end of 10 000 cycles, which was achieved via utilization of all micropores reaction sites. The EIS showed a small solution resistance of 0.75 Ω, indicating high ionic conductivity and a phase angle of – 50 °. Thus, these results show that CaAl2O4 is a potential candidate for photoluminescence and energy storage application.

Effects of synthesis conditions on particle size and pore size of spherical mesoporous silica

The particle size and pore size of spherical mesoporous silica materials play significant roles in their application. However, relatively limited systematic research has been conducted on how preparation conditions influence these properties. In particular, the effects of some important factors have not been adequately studied, including reaction time, reaction temperature, and organic solvent type. In this work, octane and water were used as solvents, and tetraethyl orthosilicate was used as the silicon source to systematically study the effects of reaction time, reaction temperature, different organic solvents, octane/water mass ratio, styrene template concentration, and surfactant (cetyltrimethylammonium bromide, CTAB)/H2O mass ratio on the particle morphology, particle size, and pore size of silica. The results suggest that the above-mentioned neglected factors exert a substantial influence on both particle size and pore size. In the experimental temperature range, the pore diameter decreases and the particle size increases with increasing temperature. The maximum particle size and pore size are achieved after a reaction time of 3 h, and a further increase in reaction time leads to a smaller particle size and pore size. As the number of carbon atoms in the organic solvent decreases, the pore size also gradually increases. Styrene and organic solvents that dissolve in CTAB micelles are crucial factors in pore formation, while the aggregation of the swollen CTAB micelles influences the particle size. The changes in the pore structure stability and hydroxyl density of the synthesized samples in water were also studied. After undergoing water treatment at temperatures ranging from 20 to 60 °C for 72 h, both the pore structure and morphology remain relatively unchanged. When the temperature increases, the surface hydroxyl density exhibits a more pronounced increase in the presence of water. After water treatment for 5 h, the surface hydroxyl density reaches saturation.

Sulfonated mesoporous TUD-1: An innovative environmentally friendly solid acid catalyst for various organic transformations

TUD-1, a novel sponge-like three-dimensional mesoporous silica material, was synthesized in one-step using a hydrothermal technique and triethanolamine as a template. To enhance its acidic properties, the TUD-1 material underwent sulfonation with varying amounts of sulfonic groups (1 and 3 wt%). Structural characteristics were determined using XRD, FTIR, Raman, BET analysis, HRTEM, SEM, and XPS. Surface acidities of the catalysts were evaluated through non-aqueous potentiometric titration and FTIR analysis of chemisorbed pyridine. The performance of catalysts was assessed in various reactions, including the Pechmann reaction, Friedel-Crafts acylation reaction, and Biginelli reaction for synthesis of 7-hydroxy-4-methyl-2H-chromen-2-one, aromatic ketones and 3, 4-dihydropyrimidin-2(1H)-one. The findings confirm that the TUD-1 mesoporous structure did not undergo any significant alteration post sulfonation. The sulfonated catalysts exhibited higher surface acidities than TUD-1. A correlation between surface acidity, particularly Brönsted acid sites, and catalytic efficiency in selected reactions was evident from both catalytic testing and characterization. Under moderate conditions, TUD-1-3SO3H exhibited outstanding catalytic performance and remarkable reusability across all selected reactions.

Synthesis of Mesoporous Silica from Palm Oil Boiler Ash (MS-POBA) with Addition of Methyl Ester Sulfonate as a Template for Free Fatty Acid Adsorption from Crude Palm Oil (CPO)

The synthesis of mesoporous material by utilizing palm oil boiler ash (POBA) waste as the silica source and methyl ester sulfonate (MES) surfactant as the template for a high-porosity was investigated for free fatty acids (FFA) adsorption. The research was initiated with silica extraction from POBA by sodium hydroxide addition through the sol-gel precipitation method. Silica modification was carried out with MES surfactant and 3-aminopropyltrimethoxysilane (APTMS) as the co-structure-directing agent (CSDA) in different calcination temperatures. Mesoporous silica-POBA (MS-POBA) free template had a surface area, pore diameter, and pore volume (41.033 m2/g, 4.180 nm, and 0.250 cm3/g) lower than MS-POBA with the template (71.0147 m2/g, 7.923 nm, and 0.524 cm3/g). The ability of MS-POBA to adsorb FFA reached its optimum conditions with an adsorption time of 20 min and an adsorbent dosage of 0.24 g. The FFA removal by MS-POBA with the template was found to have higher adsorption ability, which was 35.54%, compared to the MS-POBA free template of 26.68%. The high porosity of MS-POBA with a template makes the FFA adsorption capacity of this material higher than MS-POBA free template.