Alumina-pillared Montmorillonite Research Articles

TiO2/Al-PILC Catalysts Synthesized from a Non-Conventional Aluminum Source of Aluminum and Applied in the Photodegradation of Organic Compounds

AbstractThis study explores the transformative potential of Pillared InterLayered Clays (PILC) derived from non-conventional aluminum sources as catalytic supports in the synthesis of TiO2/catalysts for the efficient photodegradation of organic pollutants in water. Montmorillonite (Mt) and three alumina-pillared montmorillonite (PILC) synthesized using various aluminum sources, were impregnated with titanium to synthesize TiO2/catalysts. The successful synthesis of these materials was confirmed through several characterization techniques such as X-ray diffraction (XRD), N2 adsorption-desorption at -196 ºC, morphological analysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and Energy-Dispersive X-ray Spectrometry (EDX). The photolysis, adsorption, and catalytic behavior of the TiO2/catalysts were studied for the degradation of triclosan (TCS), 2,6-dichlorophenol (2,6-DCP), and bisphenol A (BPA). All synthesized catalysts surpassed the efficacy of commercial anatase, with TiO2/Al-PILC exhibiting superior performance in comparison to TiO2/Mt. Photodegradation was most effective under UV radiation, with TCS demonstrating the highest degradation (approximately 70%). Notably, Al-PILC samples, particularly those synthesized from saline slags, displayed enhanced properties. Among them, TiO2/Al-PILCAE exhibited the highest degradation rates under both UV and visible light, underlining the remarkable potential of saline slags as precursors for Al-PILC synthesis. This study provides valuable insights into the design and development of efficient catalysts for water treatment applications, paving the way for sustainable and effective solutions in the realm of environmental remediation.

The influence of cobalt loading on electrocatalytic performance toward glucose oxidation of pillared montmorillonite-supported cobalt

• Aluminum-pillared clays with different cobalt loadings were synthesized. • Modified carbon paste electrodes were tested in glucose electrooxidation. • Increase in Co loading (up to 4.13 wt%) enhanced the electrocatalytic performance. • Further increase in Co loading derogated the electrocatalytic performance. • Co 3 O 4 formation probably altered the electrocatalytic performance. In this paper, the influence of cobalt loading in pillared clay-supported cobalt materials on their electrocatalytic performance toward glucose oxidation was investigated. A series of aluminum-pillared montmorillonite clay (AP) materials with different cobalt loadings (x%CoAP, x = 1, 3, 5, and 10 wt%) was synthesized using the incipient wetness impregnation method. The X-ray powder diffraction (XRPD), inductively coupled plasma optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy coupled with energy dispersive X-ray spectrometry (FE-SEM/EDX), high resolution transmission electron microscopy (HR-TEM) coupled with EDX, X-ray photoelectron spectroscopy (XPS), and low temperature N 2 physisorption, were employed for characterization of the materials. The incorporation of cobalt in porous structure of pillared montmorillonite was confirmed. The synthesized materials (x%CoAP) were used for modification of carbon paste (CP) electrode and tested in reaction of glucose electrooxidation. The electrochemical measurements were conducted using cyclic voltammetry and chronoamperometry in a 1 M NaOH solution, with or without glucose. The results showed that the increase of cobalt loading improved the electrode performance toward glucose. The highest current response and sensitivity were obtained for the CP-5%CoAP electrode. A lower electrode performance of CP-10%CoAP was correlated with the presence of higher quantities of Co 3 O 4 (confirmed by XRPD and XPS) in the electrode material. The mechanism and kinetics of glucose electrooxidation was studied in more details for the best performing electrode (CP-5%CoAP). It was found that the process was diffusion-controlled and the diffusion coefficient was determined. The charge transfer coefficient and catalytic rate constant were calculated. The electrode exhibited satisfactory repeatability, reproducibility, stability, and selectivity. The obtained results showed that appropriate amount of cobalt loading in pillared clay led to the obtainment of non-enzymatic electrode materials suitable for sustainable and green glucose sensors.

Efficiency of Aluminium Pillared Montmorillonite Clays of Pakistani Origin (Peshawar And Samwal) on the Adsorption of Chromium Ions in Aqueous Solutions

Efficiency of Aluminium Pillared Montmorillonite Clays of Pakistani Origin (Peshawar And Samwal) on the Adsorption of Chromium Ions in Aqueous Solutions

Influence of Steam Treatment on the Properties of HLaY-Containing Cracking Catalysts in an Aluminum-Pillared Montmorillonite Matrix

A developed HLaY-containing catalyst in an aluminum-pillared montmorillonite matrix in the Na- and CaNa-forms was tested for cracking of vacuum gas oil into the target products gasoline and light gas oil. The gasoline yield increased from 58.5 to 62.5% over the steam-treated catalyst Al(2.5)CaNaHMM + HLaY. The catalyst Al(2.5)CaNaMM + HLaY on unactivated montmorillonite was tested for light gas oil production. The maximum yield of light gas oil of 65.9-65.1% was obtained after steam treatment of this catalyst at a 2:1 catalyst to feedstock ratio. The influence of steam treatment on the phase composition, porous structure, elemental composition, and acidic properties of the studied catalysts was analyzed by XRD, BET, NH3 thermal desorption, and x-ray fluorescence.

Aluminum pillared montmorillonite clay-based self-healing coatings for corrosion protection of magnesium alloy AZ91D

In the present study, aluminum pillared montmorillonite clay was modified with cationic corrosion inhibitors Ce3+/Zr4+. The modification of the montmorillonite clay was carried out by two methods; (a) by simple mixing of inhibitor solutions along with clay by stirring for 30 min and (b) by homogenization of inhibitor solutions and clay for a very short time of 15 min followed by evacuation. The modified and as-received clays were dispersed in hybrid organic-inorganic sol-gel matrix silica sol, which were coated on magnesium alloy AZ91D and cured in air at 130 °C for 1 h. Corrosion protection ability of coatings was evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss measurements after exposure to 3.5 wt% NaCl solution for different exposure durations between 24 h to 120 h. Coatings were evaluated for their self-healing ability using scanning vibrating electrode technique for varying time duration from 1 h to 24 h. Coatings generated with the sol using the pillared montmorillonite clay after modification as described in (b) were found to exhibit better anticorrosive properties even after prolonged exposure to the corrosive medium.

Synthesis and characterization of reinforced hybrid porous beads: Application to the adsorption of malachite green in aqueous solution

This study focuses on the preparation by an extrusion-dripping method of sodium alginate (SA)/aluminum-pillared montmorillonite (Al-PILMt)/polyvinyl alcohol (PVA)/calcium carbonate (CaCO3) beads using different percentages of Al-PILMt, PVA and CaCO3. Mechanical and physical characteristics of these reinforced hybrid porous beads (RHPB) were connected to the thermodynamic and kinetic adsorption properties of malachite green (MG).Mechanical properties were investigated using uniaxial compression of single wet bead. The corresponding calculated Young’s moduli were found to correlate with the PVA amount which was used in the formulation of the beads. However, these modulus values increased by approximately 70% compared to SA beads taken as references. Beads samples based on PVA and Al-PILMt prove to be more elastic with a better mechanical stability. In contrast, the addition of calcium carbonate in the mixtures leads porous beads PB with a low stiffness less than the RHB. The efficiency of RHPB was evaluated towards the elimination of MG from aqueous solutions. The dye removal, about 8% with SA beads, increased significantly with RHPB (27%) and HPB without PVA (46%). Pseudo first order kinetics with rapid initial adsorption rate and Freundlich equation are respectively used for the description of kinetic and isotherm equilibrium results. Obtained results by the principal component analysis (PCA) method showed the influence of the two main structural variations (i.e. porosity and stiffness) on their adsorption properties.

Nanoporous Copper Doped Aluminium Pillared Montmorillonite for Dye-containing Wastewater Treatment.

Copper doped aluminium pillared montmorillonite (Cu-Alpill-MMT) was prepared by adding Cu2+ into the suspension of aluminium pillared montmorillonite (Alpill-MMT) using high power ultrasonic treatment and calcining to CuO at 500 °C. The XRD and XRF data revealed that the doped CuO partially occupied both internal and external surfaces of the Alpill-MMT. The N2 adsorption/desorption analysis showed that the Cu-Alpill-MMT consisted of slit-like mesopores with two ranges of pore diameter, i.e. ~3.8 nm and ~6-30 nm. The Cu-Alpill-MMT exhibited the superior adsorption capacity for Basic Yellow 1 (BY1), however, it hardly adsorbed Reactive Orange 16 (RO16). The decolorization of RO16 was achieved when the H2O2 or H2O2/UV was introduced into the treatment system together with the Cu-Alpill-MMT, acting as heterogeneous catalyst for Fenton or photo-Fenton oxidation processes, respectively. The Cu-Alpill-MMT could exhibit the antibacterial activity after intimate contact with Escherichia coli ATCC®25922 under JIS L 1902: 1998 (Qualitative) test method.

Facile preparation of copper impregnated aluminum pillared montmorillonite: nanoclays for wastewater treatment

AbstractCopper impregnated aluminum pillared montmorillonites (Cu-iAlpill-MMTs) were prepared by adding Cu2+solution into dried aluminum polyohydroxy cation intercalated montmorillonite using various Cu2+concentrations, i.e. 4, 7, 10 and 13 wt% and then calcining at 500°C. The Cu-iAlpill-MMTs possessed slit-liked mesopores with pore diameters of 3.3–3.8 nm and ~6–35 nm as observed from the nitrogen adsorption isotherms. The mesopore quantities of Cu-iAlpill-MMTs gradually decreased with the increase of impregnated Cu2+concentrations. The impregnated CuO occupied not only the interior interlayers, but also the exterior surfaces of Cu-iAlpill-MMTs. The Cu-iAlpill-MMTs with 10 and 13 wt% of impregnated Cu2+could inhibit the growth ofEscherichia coli. The Cu-iAlpill-MMTs effectively acted as the heterogeneous catalyst for removal reactive orange 16 (RO16) in Fenton or photo-Fenton oxidation treatments. The higher impregnated Cu2+and/or the longer treatment time brought about the higher percentage of RO16 removal.

Preparation of Alumina Pillared Montmorillonite Clays Employing Ultrasonics and Their Catalytic Properties

<p>An accelerated diffusion of alumina precursor species in-between the gallery region of montmorillonite clays by the use of ultrasonic technique is described. This method offers a faster, efficient and attractive route for the synthesis of alumina-pillared clay catalysts. Out of the several preparative parameters studied, the role of pre-exchanged cations influenced the optimum duration of ultrasonic agitation and treatment for the pillaring process. By comparing ultrasonic route and conventional preparation procedure, it is revealed that uniform spacing of alumina pillars in the clay means homogeneously distributed acid centers. The influence of calcination temperature on the acidity and hence the catalytic activity is described. The choice of three different montmorillonite clays with different cation exchange capacities enables one to tune the pore dimensions of the pillared clays. The catalytic applications include studies on cumene cracking, dehydration of propan-2-ol and alkylation of benzene with linear olefins. </p>

Synthesis, Characterization and Aplication of TiO2 Alumina Pillared Montmorillonite Photocatalyst

Dispersion of TiO2 on montmorillonite pillared aluminium has been done successfully. The photocatalyst were prepared by intercalation of Al13 onto natural montmorillonite and then calcined at 500oC. Titania dispersion onto aluminium pillared montmorillonite was carried out by impregnation method at the theoritic concentration of 0.4, 0.8, 1 and 3% titania. The photocatalyst then characterized by XRD, porosimetry, SEM and Diffuse Reflectance Visible methods. Results of characterization showed that the basal spacing and specific surface area as well as total pore volume were decreased after dispersion of TiO2 on PILM, meanwhile SEM image exhibited that beside in the pores of PILM, the TiO2 was also dispersed on the surface of PILM. DR UV characterization result indicated that the band gap of TiO2 dispersed PILM for Ti/PILM 0,8%, Ti/PILM 1% and Ti/PILM 3% was 3.66, 3.19 and 3.19 eV respectively. Photodegradation optimum of methyl orange was found to be at Ti/PILM 1% Keywords : montmorillonite, pillarization, photocatalyst, methyl orange, TiO2

Simultaneous sorption of 4-nitrophenol and 2-nitrophenol on a hybrid geocomposite based on surfactant-modified pillared-clay and activated carbon

New generations of hydrophobic composite geomaterials intended to sorb certain hazardous wastes are assembled by mixing surfactant-modified aluminum-pillared montmorillonite (Al-SMPM) with activated carbon (AC). The sorption of 4-nitrophenol (4NP) and 2-nitrophenol (2NP) on these sorbents was studied in both single and binary component systems from aqueous solutions using batch tests. Results showed the efficiency of these composite sorbents relative to the two phenolic compounds, with a dominant contribution from Al-SMPM. In single-component systems, sorption isotherms of 4NP and 2NP as a function of pH were analyzed with the Freundlich equation, whose statistical interpretation was also developed. Sorption capacities sharply decreased when the solution pH value was raised from 3 to 9. In binary-component systems, the fit between measured and predicted simultaneous sorption capacities of both 4NP and 2NP indicated that the Sheindorf–Rebhun–Sheintuch model, an extended Freundlich model, is fully applicable. The 2NP favorably influences the sorption of 4NP. The synergistic effect between these two nitrophenol compounds has been confirmed by the higher competition coefficients, which increase with increasing pH. A number of hypotheses, based on the Abraham’s solvation parameters model, have been advanced to discuss this mechanism.

Catalysts based on pillared clays for the oxidation of chlorobenzene

The aim of this work was to reveal the main factors which affect the oxidation of chlorobenzene (PhCl) over palladium and platinum supported on alumina pillared clays. The catalysts were prepared by wet impregnation of an alumina-pillared montmorillonite (Al-PILC) with palladium and platinum solutions and characterized by several physicochemical techniques before and after the catalytic tests. During oxidation of PhCl over the catalysts, the formation of carbon dioxide along with small quantities of carbon monoxide, PhClx and coke was found. The nature of the supported metal, the temperature, the metal loading, the support, and the time on stream, are factors affecting the combustion of PhCl.

Cracking of heavy vacuum gas oils over (HCeY) zeolite-containing, aluminum-pillared montmorillonite and activated kaolinite clays

Zeolite-containing HCeY catalysts on aluminum-pillared montmorillonites and activated kaolinites with a mesoporous structure have been tested in the cracking of heavy vacuum gas oils. The activities of the zeolite-containing and zeolite-free catalysts have been compared. The highest yields of gasoline and light cycle oil have been obtained on the Al(5.0)NaHMM + HCeY catalyst and the zeolite-free AlHKE kaolinite contact, respectively.

Preparation of ZrO2/Al2O3-montmorillonite composite as catalyst for phenol hydroxylation

Zirconium dispersed in aluminum-pillared montmorillonite was prepared as a catalyst for phenol hydroxylation. The effects of varying the Zr content on the catalyst’s physicochemical character and activity were studied with XRD, BET surface area analysis, surface acidity measurements and scanning electron microscopy before investigating the performance for phenol conversion. The zirconia dispersion significantly affects the specific surface area, the total surface acidity and surface acidity distribution related to the formation of porous zirconia particles on the surface. The prepared samples exhibited excellent catalytic activity during phenol hydroxylation.

Isomerization of α-Pinene over Alumina-Pillared Montmorillonite

In this work, the liquid phase catalytic isomerization of α-pinene over alumina-pillared montmorillonitewas investigated, and the influence of reaction temperature, reaction time and amount of the catalyston the conversion of α-pinenewere discussed systematically, and the optimum reaction conditions forisomerization of α-pineneover alumina-pillared montmorillonitewere obtained. The basal spacing of thealumina-pillared montmorillonite was characterized by X-ray diffraction, and the liquid reactant was separated and identified by gas chromatography. The result showed that alumina-pillared montmorillonite with 1.83nm of basal spacing exhibited a high catalytic activity for the isomerization of α-pinene, and 97.4% conversion of α-pinene was achievedat 373K for 3hwhen the mass ratio of catalyst to α-pinene was 1/10.

Mild Temperature Oxidation of Phenol over Rare Earth Exchanged Aluminum Pillared Montmorillonites

Wastewater treatment and re-use of industrial process water are critical issues for the developmentof human activities and environment conservation. The present study was undertaken to evaluate the degradationof organic pollutants taking phenol as the model compound over aluminium pillared montmorillonite and therare earth exchanged analogues, underlining the use of environ friendly clay catalysts for the effective removalof water pollutants. From the study it was noted that for reaction variables like temperature, peroxide load,catalyst load, phenol concentration etc, optimal values exist that must be taken into account for obtaining bestresults. The catalysts used were aluminium pillared montmorillonite prepared by partial hydrolysis methodexchanged with La, Ce and Th metal salts at room temperature. Characterisation of the prepared systems weredone using X-ray diffraction and surface area and pore volume measurements.The pillared montmorilloniteshowed considerable increase in basal spacing and BET surface area compared to parent montmorillonite.

Adsorption of Molecules with Different Shapes on Alumina-pillared Montmorillonite with Different Amount of Pillar

Adsorption of Molecules with Different Shapes on Alumina-pillared Montmorillonite with Different Amount of Pillar

Methylene Blue Adsorption on Alumina-Pillared Montmorillonite with Different Amount of Pillar

Methylene Blue Adsorption on Alumina-Pillared Montmorillonite with Different Amount of Pillar

Effect of Aluminium Content in Aluminium Pillared Montmorillonite on Its Surface Acidity Properties

Aluminium pillared montmorillonites from Indonesian natural montmorillonite has been prepared using Al13 Keggin ion pillaring precursor in varied concentrations. Herein we studied their characterization and catalysis application for esterification reaction. X-ray diffraction (XRD), energy dispersive x-ray analysis (EDX), and BET gas sorption analysis were employed to characterize the prepared materials besides the characterization on surface acidity by pyridine and n-butylammine adsorptions and FTIR analysis. The result showed that significant improvement on physicochemical character data was obtained by a pillarization process. Such a process also provided improvements on catalytic activities in esterification reactions. The effect of aluminium content on material characters was discussed in this paper. It was observed from the catalytic activity tests that pillared montmorillonite samples demonstrated higher activity in esterification reaction relative to the raw montmorillonite. It was found that surface profile of materials consist of specific surface area, pore volume and Lewis acidity were significantly affect the catalyst activity.

Physicochemical characterization of vanadium-doped alumina-pillared montmorillonite catalyst: Epoxidation of trans-2-hexen-1-ol

V-doped alumina-pillared montmorillonite catalysts, obtained by different methods, have been characterized by XRD, ESR, nitrogen adsorption and chemical analysis. All of the samples are microporous, but their structure, texture and location of vanadium species depend on the method of preparation. Catalytic results for the reaction of epoxidation of trans-2-hexen-1-ol are discussed in terms of the physicochemical properties of the materials.