Utilizing Gelatin Waste for Efficient Bimodal Porous Silica Adsorbents for Carbon Dioxide Capture.

This study explores the modification of pore structures in porous silica materials synthesized using sodium silicate and waste gelatin, under varying silica-to-gelatin ratios. At ratios of 1.0-1.5, bimodal porous silica with mesopores and macropores emerged due to spaces between silica nanoparticles and clusters, following gelatin elimination. The study further evaluated the obtained bimodal porous silica as polyethyleneimine (PEI) supports for CO2 capture, alongside PEI-loaded unimodal porous silica and hollow silica sphere for comparison. Notably, the PEI-loaded bimodal silica showcased superior CO2 uptake, achieving 145.6 mg g-1 at 90 °C. Transmission electron microscopy (TEM) revealed PEI's uniform distribution within the pores of bimodal silica, unlike the excessive surface layering seen in unimodal silica. Conversely, PEI completely filled the hollow porous silica's interior, extending gas molecule diffusion distance. All sorbents displayed nearly constant CO2 adsorption across 20 cycles, demonstrating outstanding stability. Notably, the bimodal porous silica displayed a negligible capacity loss, underscoring its robust performance.

Long-term evaluation of palm oil mill effluent (POME) steam reforming over lanthanum-based perovskite oxides.

To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO3 and net-basic LaCoO3 were proposed as the POME primary treatments, with promising H2-rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74-105 µm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO3 (50.54 wt%) had similar carbon deposition with spent LaNiO3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La2O2CO3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La2O2CO3 decarbonation occurred continuously in LaCoO3 system but intermittently in LaNiO3 system. LaNiO3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO3 system offered greater net H2 production (72.78%) and POME treatment volume (30.77%) than LaNiO3 system. SR could attain appreciable POME degradation (>97% COD, BOD5, TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD5.

Unraveling the roles of microporous and micro-mesoporous structures of carbon supports on iron oxide properties and As (V) removal performance in contaminated water.

This study investigates the impact of microporous (SP-C) and micro-mesoporous carbon (DP-C) supports on the dispersion and phase transformation of iron oxides and their arsenic (V) removal efficiency. The research demonstrates that carbon-supported iron oxide sorbents exhibit superior As(V) uptake capacity compared to unsupported Fe2O3, attributed to reduced iron oxide crystallite sizes and As(V) adsorption on carbon supports. Maximum As(V) uptake capacities of 23.8 mg/g and 18.9 mg/g were achieved for Fe/SP-C and Fe/DP-C at 30 wt% and 50 wt% iron loading, respectively. The study reveals a nonlinear relationship between As(V) sorption capacity and iron oxide crystallite size after excluding As(V) adsorption capacity on carbon supports, suggesting the iron oxide phase (Fe3O4) plays a role in determining adsorption capacity. Iron oxide-loaded DP-C sorbents exhibit faster adsorption rates at low As(V) concentrations (5 mg/L) than SP-C sorbents due to their bimodal pore structure. Adsorption behavior varies at higher As(V) concentrations (45 mg/L), with Fe/DP-C reaching maximum capacity more slowly due to limited available adsorptive sites. All adsorbents maintained near-complete As(V) removal efficiency over five cycles. The findings provide insights for designing more efficient adsorbents for As(V) removal from contaminated water sources.

Rice husk waste into various template-engineered mesoporous silica materials for different applications: A comprehensive review on recent developments.

Following the discovery of Stöber silica, the realm of morphology-controlled mesoporous silica nanomaterials like MCM-41, SBA-15, and KCC-1 has been expanded. Due to their high BET surface area, tunable pores, easiness of functionalization, and excellent thermal and chemical stability, these materials take part a vital role in the advancement of techniques and technologies for tackling the world's largest challenges in the area of water and the environment, energy storage, and biotechnology. Synthesizing these materials with excellent physicochemical properties from cost-efficient biomass wastes is a foremost model of sustainability. Particularly, SiO2 with a purity >98% can be obtained from rice husk (RH), one of the most abundant biomass wastes, and can be template engineered into various forms of mesoporous silica materials in an economic and eco-friendly way. Hence, this review initially gives insight into why to valorize RH into value-added silica materials. Then the thermal, chemical, hydrothermal, and biological methods of high-quality silica extraction from RH and the principles of synthesis of mesoporous and fibrous mesoporous silica materials like SBA-15, MCM-41, MSNs, and KCC-1 are comprehensively discussed. The potential applications of rice husk-derived mesoporous silica materials in catalysis, drug delivery, energy, adsorption, and environmental remediation are explored. Finally, the conclusion and the future outlook are briefly highlighted.

Hydrothermal synthesis temperature induces sponge-like loose silica structure: A potential support for Fe2O3-based adsorbent in treating As(V)-contaminated water.

Low cost Fe2O3-based sorbents with an exceptional selectivity toward the targeted As(V) pollutant have gained extensive attention in water treatment. However, their structural features often influence removal performance. In this respect, we present herein a rational design of silica-supported Fe2O3 sorbents with an enhanced morphological structure based on a simple temperature-induced process. Low-hydrothermal temperature synthesis (60 and 100 °C) provided a large silica-cluster size with a close packed structure (S-60 and S-100), contributing to an increase in mass transport resistance. Fe2O3/S-60 with 6.2-nm pore width silica achieved a maximum As(V) uptake capacity (qm) of only 3.5 mg g-1. Supporting Fe2O3 on S-100 with an approximately two-fold increase in the pore size (13 nm) did not lead to any evident enhancement in qe (3.7 mg g-1). However, expanding the pore window up to 22.6 nm (S-140) and 39.5 nm (S-180), along with changing from close-packed to sponge-like loose structures induced by high-temperature synthesis (140 °C and 180 °C), resulted in substantial increases in qm. Fe2O3/S-140 had 1.7 and 1.6 times higher qm (5.9 mg g-1) than Fe2O3/S-100 and Fe2O3/S-60, respectively. The highest qm (7.4 mg g-1) was achieved for Fe2O3/S-180, which was attributed to its relatively small-sized silica cluster and the largest cavities that facilitated easier access by As(V) to adsorbing sites.

Fe2O3-decorated hollow porous silica spheres assisted by waste gelatin template for efficient purification of synthetic wastewater containing As(V).

Purification of As(V)-contaminated water through adsorption by Fe2O3-based materials is a promising technology due to its low-cost and high efficiency. Dispersing the Fe2O3 phase on silica supports can improve both the adsorption rate and capacity due to the reduction in Fe2O3 particle sizes and the prevention of clumping of the Fe2O3 particles. However, the clusters in conventional silica materials largely impede the diffusion of As(V) to reach the Fe2O3 sites dispersed inside the clusters. Here, by applying a gelatin template strategy, the structure of silica materials was tailored by changing the gelatin-to-silica ratio (0, 0.6, 1.2 and 1.8) and hydrothermal temperature (60 °C, 100 °C and 140 °C). The silica cluster size could be reduced using either a low gelatin-to-silica ratio (0.6) or a low hydrothermal temperature (60 °C). Increasing the gelatin-to-silica ratio to 1.2 created porous silica spheres with a hollow structure. The Fe2O3-loaded hollow porous silica spheres with a shell thickness of 280 nm had twice the maximum As(V) adsorption capacity (7.66 mg g-1) compared to the Fe2O3-loaded silica product prepared in the absence of gelatin (3.82 mg g-1). The maximum As(V) adsorption capacity could be further enhanced to 9.94 mg g-1 by reducing the shell thickness to 80 nm through increasing the gelatin-to-silica ratio to 1.8 and the hydrothermal temperature to 140 °C. In addition, the best Fe2O3-loaded hollow porous silica spheres had rapid As(V) adsorption and showed excellent durability as the As(V) removal efficiency slightly decreased to 98.9% subsequent to five adsorption-regeneration cycles.

Rapid effectual entrapment of arsenic pollutant by Fe2O3 supported on bimodal meso-macroporous silica for cleaning up aquatic system.

Arsenic (As) contamination in aqueous media is a major concern due to its adverse impacts on humans and the ecosystem more broadly because of its non-biodegradability. Consequently, an effective and selective sorbent is needed urgently to scavenge As pollutant. Herein, the adsorption behaviors of As(V) by Fe2O3 and Fe2O3 supported on different silica materials, consisting of unimodal mesoporous silica (Fe2O3/U-SiO2) and dual meso-macroporous silica (Fe2O3/B-SiO2), were compared to examine their structure-efficiency relationships in the elimination of As(V). Fe2O3/B-SiO2 was much faster at As(V) removal and had an impressively higher uptake capability, reaching nearly 50% and 2.5 mg g-1 within 5 min compared to bare Fe2O3 (6% and 0.3 mg g-1) and Fe2O3/U-SiO2 (11.9% and 0.59 mg g-1). These better results were because of the highly dispersed Fe2O3 nanoparticles on the B-SiO2 support that provided abundant reactive sites as well as a macropore structure facilitating As(V) diffusion into adsorptive sites. The maximum adsorptive capacity of Fe2O3/B-SiO2 (4.7 mg As per 1 g adsorbent) was 1.3- and 1.7-fold greater than for Fe2O3/U-SiO2 and Fe2O3, respectively. The outstanding performance and reusability of Fe2O3/B-SiO2 with its ease of production, economical and environmentally friendly features made it even more attractive for As(V) remediation. The explored relationship between the structure of SiO2-supported Fe2O3 sorbents and their performance in removing As(V) could be informative for the future design of highly efficient adsorbents for the decontamination of water.

Oxidative coupling of methane-comparisons of MnTiO3-Na2WO4 and MnOx-TiO2-Na2WO4 catalysts on different silica supports.

The oxidative coupling of methane (OCM) converts CH4 to value-added chemicals (C2+), such as olefins and paraffin. For a series of MnTiO3-Na2WO4 (MnTiO3-NW) and MnOx-TiO2-Na2WO4 (Mn-Ti-NW), the effect of loading of MnTiO3 or MnOx-TiO2, respectively, on two different supports (sol-gel SiO2 (SG) and commercial fumed SiO2 (CS)) was examined. The catalyst with the highest C2+ yield (21.6% with 60.8% C2+ selectivity and 35.6% CH4 conversion) was 10 wt% MnTiO3-NW/SG with an olefins/paraffin ratio of 2.2. The catalyst surfaces with low oxygen-binding energies were associated with high CH4 conversion. Stability tests conducted for over 24 h revealed that SG-supported catalysts were more durable than those on CS because the active phase (especially Na2WO4) was more stable in SG than in CS. With the use of SG, the activity of MnTiO3-NW was not substantially different from that of Mn-Ti-NW, especially at high metal loading.

Biomass-derived carbon-based and silica-based materials for catalytic and adsorptive applications- An update since 2010.

Biomass, which defined as plant- or animal-based materials, is intriguing tremendous scientific attentions due to its renewable attribute in serving energy security. Amongst, the plant-based biomasses, particularly those that co-generated in the agriculture activities, are commonly regarded as fuel for burning, which overlooked their hidden potentials for high-end applications. Organically, the plant-based biomass constitutes of lignocellulose components, which can be served as promising precursors for functionalized carbon materials. Meanwhile, its inorganic counterpart made up of various minerals, with Si being the most concerned one. With the advancement of biomass technologies and material synthesis in recent years, numerous attempts were endeavoured to obtain valorised products from biomass. Particularly, syntheses of catalytic and adsorptive materials are actively researched in the field of biomass reutilization. Herein, our work systematically summarized the advancements of biomass-materials for these applications in recent 10 years (2010-2020), with a special focus on the carbon-based and Si-based catalytic/adsorptive materials. Significantly, the deriving steps, inclusive of both pre-treatment and post-treatment of such materials, are incorporated in the discussion, alongside with their significances revealed too. The performance of the as-obtained materials in the respective application is systematically correlated to their physicochemical properties, hence providing valuable insights to the readers. Challenges and promising directions to be explored are raised too at the end of the review, aiming to advocate better-usage of biomass while offering great opportunities to sustain catalysis and adsorption in the industrial scale.

Highly efficient TiO2-supported Co-Cu catalysts for conversion of glycerol to 1,2-propanediol.

Glycerol is a low-cost byproduct of the biodiesel manufacturing process, which can be used to synthesize various value-added chemicals. Among them, 1,2-propanediol (1,2-PDO) is of great interest because it can be used as an intermediate and additive in many applications. This work investigated the hydrogenolysis of glycerol to 1,2-PDO over Co-Cu bimetallic catalysts supported on TiO2 (denoted as CoCu/TiO2) in aqueous media. The catalysts were prepared using the co-impregnation method and their physicochemical properties were characterized using several techniques. The addition of appropriate Cu increased the glycerol conversion and the 1,2-PDO yield. The highest 1,2-PDO yield was achieved over a 15Co0.5Cu/TiO2 catalyst at 69.5% (glycerol conversion of 95.2% and 1,2-PDO selectivity of 73.0%). In the study on the effects of operating conditions, increasing the reaction temperature, initial pressure, and reaction time increased the glycerol conversion but decreased the selectivity to 1,2-PDO due to the degradation of formed 1,2-PDO to lower alcohols (1-propanol and 2-propanol). The reaction conditions to obtain the maximum 1,2-PDO yield were a catalyst-to-glycerol ratio of 0.028, a reaction temperature of 250 °C, an initial H2 pressure of 4 MPa, and a reaction time of 4 h.

A review on advances in green treatment of glycerol waste with a focus on electro-oxidation pathway.

Over the past decades, research efforts are being devoted into utilizing the biomass waste as a major source of green energy to maintain the economic, environmental, and social sustainability. Specifically, there is an emerging consensus on the significance of glycerol (an underutilised waste from biodiesel industry) as a cheap, non-toxic, and renewable source for valuable chemicals synthesis. There are numerous methods enacted to convert this glycerol waste to tartronic acid, mesoxalic acid, glyceraldehyde, dihydroxyacetone, oxalic acid and so on. Among these, the green electro-oxidation technique is one of the techniques that possesses potential for industrial application due to advantages such as non-toxicity process, fast response, and lower energy consumption. The current review covers the general understanding on commonly used techniques for alcohol (C1 & C2) conversion, with a specific insight on glycerol (C3) electro-oxidation (GOR). Since catalysts are the backbone of chemical reaction, they are responsible for the overall economy prospect of any processes. To this end, a comprehensive review on catalysts, which include noble metals, non-noble metals, and non-metals anchored over various supports are incorporated in this review. Moreover, a fundamental insight into the development of future electrocatalysts for glycerol oxidation along with products analysis is also presented.

Sustainable utilization of waste glycerol for 1,3-propanediol production over Pt/WOx/Al2O3 catalysts: Effects of catalyst pore sizes and optimization of synthesis conditions.

Recycling of waste glycerol derived from biodiesel production to high value-added chemicals is essential for sustainable development of Bio-Circular-Green Economy. This work studied the conversion of glycerol to 1,3-propanediol over Pt/WOx/Al2O3 catalysts, pointing out the impacts of catalyst pore sizes and operating conditions for maximizing the yield of 1,3-propanediol. The results suggested that both pore confinement effect and number of available reactive metals as well as operating conditions determined the glycerol conversion and 1,3-propanediol selectivity. The small-pore 5Pt/WOx/S-Al2O3 catalyst (6.1 nm) gave a higher Pt dispersion (32.0%), a smaller Pt crystallite size (3.5 nm) and a higher number of acidity (0.47 mmol NH3 g-1) compared to those of the large-pore 5Pt/WOx/L-Al2O3 catalyst (40.3 nm). However, glycerol conversion and 1,3-propanediol yield over the small-pore 5Pt/WOx/S-Al2O3 catalyst were significantly lower than those of the large-pore Pt/WOx/L-Al2O3 catalyst, suggesting that the diffusional restriction within the small-pore catalyst suppressed transportation of molecules to expose catalytic active sites, favoring the excessive hydrogenolysis of 1,3-propanediol, giving rise to undesirable products. The best 1,3-propanediol yield of 32.8% at 78% glycerol conversion were achieved over the 5Pt/WOx/L-Al2O3 under optimal reaction condition of 220 °C, 6 MPa, 5 h reaction time and amount of catalyst to glycerol ratio of 0.25 g mL-1. However, the 1,3-propanediol yield and glycerol conversion decreased to 19.6% and 51% after the 4th reaction-regeneration which were attributed to the carbonaceous deposition and the agglomeration of Pt particles.

Effect of Water and Glycerol in Deoxygenation of Coconut Oil over Bimetallic NiCo/SAPO-11 Nanocatalyst under N2 Atmosphere.

The catalytic deoxygenation of coconut oil was performed in a continuous-flow reactor over bimetallic NiCo/silicoaluminophosphate-11 (SAPO-11) nanocatalysts for hydrocarbon fuel production. The conversion and product distribution were investigated over NiCo/SAPO-11 with different applied co-reactants, i.e., water (H2O) or glycerol solution, performed under nitrogen (N2) atmosphere. The hydrogen-containing co-reactants were proposed here as in-situ hydrogen sources for the deoxygenation, while the reaction tests under hydrogen (H2) atmosphere were also applied as a reference set of experiments. The results showed that applying co-reactants to the reaction enhanced the oil conversion as the following order: N2 (no co-reactant) < N2 (H2O) < N2 (aqueous glycerol) < H2 (reference). The main products formed under the existence of H2O or glycerol solution were free fatty acids (FFAs) and their corresponding Cn-1 alkanes. The addition of H2O aids the triglyceride breakdown into FFAs, whereas the glycerol acts as hydrogen donor which is favourable to initiate hydrogenolysis of triglycerides, causing higher amount of FFAs than the former case. Consequently, those FFAs can be deoxygenated via decarbonylation/decarboxylation to their corresponding Cn-1 alkanes, showing the promising capability of the NiCo/SAPO-11 to produce hydrocarbon fuels even in the absence of external H2 source.

Synthesis of Dimethyl Ether via CO2 Hydrogenation: Effect of the Drying Technique of Alumina on Properties and Performance of Alumina-Supported Copper Catalysts.

Thermal treatment during catalyst preparation is one of the important factors affecting the characteristics and performance of a catalyst. To improve the catalytic performance of an alumina-supported copper catalyst prepared by an impregnation method for dimethyl ether (DME) synthesis from CO2, the effects of the use of hot air and infrared drying as well as calcination at 600 and 900 °C to prepare alumina supports were investigated. Infrared drying could shorten the required drying time by 75% when compared with hot air drying. Infrared drying could also help maintain the pore size and pore volume of the supports, leading to their larger surface areas. Different drying techniques were additionally noted to result in different sizes and shapes of the pores as well as to different copper distributions and intensities of acid sites of the catalyst. An increase in the calcination temperature resulted in a decrease in the surface area of the supports because of particle aggregation. The drying technique exhibited a more significant effect than calcination temperature on the space-time yield of DME. A catalyst utilizing the support prepared by infrared drying and then calcined at 600 °C exhibited the highest yield of DME (40.9 gDME kgcat -1 h-1) at a reaction temperature of 300 °C. Stability of the optimal catalyst, when monitored over a 24 h period, was noted to be excellent.

Tailoring hierarchical zeolite composites with two distinct frameworks for fine-tuning the product distribution in benzene alkylation with ethanol.

A hierarchical zeolite composite, MOR@ZSM-5, with two distinct frameworks has been successfully fabricated via the repeated crystallization of ZSM-5 nanocrystals on mordenite surfaces. To avoid their phase separation, the surface of mordenite was pretreated with tetra(n-butyl)ammonium hydroxide (TBAOH) to induce the formation of the ZSM-5 nuclei, and it was subsequently modified by the continuous growth of nanocrystalline ZSM-5 on the entire area of the mordenite surfaces. Interestingly, the fully overgrown MOR@ZSM-5 composite exhibits a remarkable improvement in the ethylbenzene selectivity (>60%) obtained from the alkylation of benzene with ethanol with respect to isolated zeolites and their physical mixture due to the enhanced external surface area and hierarchical porosity as well as the reasonable acidity provided by the fully dispersed ZSM-5 nanocrystals on the mordenite surfaces. Moreover, coke species deposited on the designed composites are likely located at the external surfaces and do not considerably deteriorate the catalytic performance, whereas they are deposited predominantly in the micropores over the incompletely overgrown MOR@ZSM-5 composite. The present study illustrates the advantages of the overgrown zeolite composites of two incompatible frameworks in tailoring the hierarchical porosity, adjusting the acidic properties, and eventually controlling the product selectivity in acid-catalyzed reactions such as the alkylation of benzene with ethanol.

Facile synthesis of CaFe2O4 for visible light driven treatment of polluting palm oil mill effluent: Photokinetic and scavenging study.

In this paper, a facile synthesis method for CaFe2O4 is introduced that produces a catalyst capable of significant photocatalytic degradation of POME under visible light irradiation. The co-precipitation method was used to produce two catalysts at calcination temperatures of 550 °C and 700 °C dubbed CP550 and CP700. CP550 demonstrated the maximum COD removal of 69.0% at 0.75 g/L catalyst loading after 8 h of visible light irradiation which dropped to 61.0% after three consecutive cycles. SEM images indicated that the higher calcination temperature of CP700 led to annealing which reduced the pore volume (0.025 cm3/g) and pore diameter (10.3 nm) while simultaneously creating a smoother and more spherical surface with lower SBET (9.73 m2/g). In comparison, CP550 had a rough hair-like surface with higher SBET (27.28 m2/g) and pore volume (0.077 cm3/g) as evidenced by BET analysis. XRD data indicated the presence of CaFe5O7 in the CP550 composition which was not present in CP700. The presence of Wustite-like FeO structures in CaFe5O7 are likely the cause for lower photoluminescence intensity profile and hence better charge separation of CP550 as these structures in CaFe2O4 have been known to increase resistivity and electron localization. The COD removal of CP550 dropped from 69.0% to just 7.0% upon adding a small quantity of isopropanol into the reaction mixture indicating hydroxyl radicals as the primary reactive oxidative species.

Nanoceria-modified platinum supported on hierarchical zeolites for selective alcohol oxidation.

The highly selective oxidation of alcohols to aldehydes has been achieved due to the synergic effect of Pt and CeO2 supported on hierarchical zeolites. The combination of Pt and CeO2 strongly enhances the catalytic performance of the oxidation of benzyl alcohol to benzaldehyde with respect to the isolated materials. In addition, the hierarchical zeolite not only increases the fraction of exposed active sites because of its high surface area that can prevent the aggregation of Pt and CeO2 nanoparticles, but also affects the oxidation state of cerium. The presence of a high content of trivalent Ce species (Ce3+) on the hierarchical zeolite benefits the oxidation reaction, eventually leading to almost 100% yield of an aldehyde product. Moreover, the catalytic performance can be further improved by the easily tunable Si to Al ratio of zeolite catalysts.

Impact of pore characteristics of silica materials on loading capacity and release behavior of ibuprofen.

Impact of pore characteristics of porous silica supports on loading capacity and release behavior of ibuprofen was investigated. The porous silica materials and ibuprofen-loaded porous silica materials were thoroughly characterized by N2-sorption, thermal gravimetric and derivative weight analyses (TG-DTW), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) to determine the physical properties of materials, amount of ibuprofen adsorbed and position of ibuprofen. The detailed characterization reveals that the ibuprofen molecules adsorbed inside the mesopores. Increasing the mesopore size from 5nm to 10nm increased the ibuprofen loading from 0.74 to 0.85mmol/g, respectively. Incorporation of macropore into the structure of porous silica materials enhanced the ibuprofen loading capacity of 11.8-20.3%. The ibuprofen-loaded bimodal meso-macroporous silica materials exhibited the highest dissolution of 92wt.% within an hour. The ibuprofen particles deposited on the external surface of the porous silica materials showed a lower dissolution rate than the ibuprofen adsorbed inside the mesopores due to the formation of ibuprofen crystalline.

Biodiesel production from transesterification of palm oil with methanol over CaO supported on bimodal meso-macroporous silica catalyst.

Calcium oxide-loaded porous materials have shown promise as catalysts in transesterification. However, the slow diffusion of bulky triglycerides through the pores limited the activity of calcium oxide (CaO). In this work, bimodal meso-macroporous silica was used as a support to enhance the accessibility of the CaO dispersed inside the pores. Unimodal porous silica having the identical mesopore diameter was employed for the purpose of comparison. Effects of CaO content and catalyst pellet size on the yield of fatty acid methyl esters (FAME) were investigated. The basic strength was found to increase with increasing the CaO content. The CaO-loaded bimodal porous silica catalyst with the pellet size of 325µm achieved a high %FAME of 94.15 in the first cycle, and retained an excellent %FAME of 88.87 after five consecutive cycles.