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The thermal power plants produce huge quantity of fly ash as waste materials, and dumped in to the ash dykes, which occupies several acres of land and ultimately, spoil it. Researchers are looking for the reasonable treatment process to convert the fly ash into useful materials like zeolites. In this work, fly ash derived Mordenite zeolite has been synthesized with improved catalytic activity. The utility of this material is demonstrated as a solid acid catalyst for the synthesis of n-butyl levulinate from biomass derived levulinic acid. This study demonstrates successful cost effective transformation of fly ash into environmentally benign catalyst.

The aim of this work was to carry out an experimental study along with kinetic and thermodynamic analysis for the toluene disproportionation reaction under actual industrial operating conditions. The toluene disproportionation reaction was carried out under pressurized hydrogen and over three different ZSM-5 based catalysts, namely, ZSM-5, 3%Mo on ZSM-5, and 3%Mo on ZSM-5/Mordenite. The influence of reaction temperature and catalyst composition on conversion and product distribution was investigated. A network of reversible reactions and elementary rate laws reflecting the product distribution, including xylene isomers and other products, were proposed and validated using the obtained experimental data. The thermodynamic parameters were estimated using a chemical process simulation package (Aspen HYSYS), while numerical and statistical methods were used to estimate the kinetic parameters. A notable agreement between the model predictions and the experimental data was obtained. The Mo-impregnated, mordenite-containing catalyst (3%Mo on ZSM-5/Mordenite) was found to be the most active catalyst, presumably due to the additional metallic-active sites that were readily accessible through the mordenite's large pores compared to the plain ZSM-5 catalyst. In addition, the most active catalyst was found to have the lowest activation energies and lead to conversions that were limited thermodynamically.

Abstract A mesoporous mordenite (MOR) zeolite was prepared from a commercially available MOR sample by a sequential acid-alkaline-acid post-treatment. The latter was used as support of Pt to prepare a bifunctional Pt/H-MOR catalyst for the hydroisomerization of n -hexane. The results showed that the available mesopores in the catalyst shorten the diffusion length of reactants and of the produced branched hexanes inside the micropores. In addition, the dispersion of supported Pt in the zeolite was increased and an enhancement in the conversion of n -hexane and at the same time the reduction of the non-selective cracking of hexane isomers and of the formation of coke (catalyst deactivation) was observed. Graphical abstract Unlabelled Image Highlights • Mesoporous MOR prepared by a sequential acid-alkaline-acid post-treatment • Microporosity and acidity well preserved in the mesoporous MOR • The introduced mesoporosity helps the dispersion of Pt on the MOR • The mesoporosity enhances the catalytic hydroisomerization rate of n -hexane • The mesoporosity improves the catalyst stability [ABSTRACT FROM AUTHOR]

Abstract The selective catalytic hydrogenation of acetophenone (AP)to 1-phenylethanol (PhE) has been studied in water, ethanol and n-hexanesolvent over Co/mordenite. It was shown that the highest yield of PhE (99.9%) was obtained in water solvent. The adsorption of AP hindered the adsorption of PhE in water, which in turn reduced the rate of hydrogenolysis of PhE to ethylbenzene (EB).By increasing the reaction temperature the hydrogenolysis of PhE to EB is promoted. The water phase was collected after reaction and reused successfully. The yield of PhE was 96.1% when the AP concentration in solution and the catalyst loading increased to three times. The neutral and alkaline conditions were beneficial to the hydrogenation of AP to PhE in water. Graphical abstract Unlabelled Image Highlights • The highest yield of PhE(99.9%) was obtained in water on Co/mordenite. • The hydrogenolysis of PhE to EB was inhibited in water. • The water solvent water could be reused successfully. • The neutral and alkaline condition is benefical to the hydrogenation of AP in water. [ABSTRACT FROM AUTHOR]

The thermal power plants produce huge quantity of fly ash as waste materials, and dumped in to the ash dykes, which occupies several acres of land and ultimately, spoil it. Researchers are looking for the reasonable treatment process to convert the fly ash into useful materials like zeolites. In this work, fly ash derived Mordenite zeolite has been synthesized with improved catalytic activity. The utility of this material is demonstrated as a solid acid catalyst for the synthesis of n-butyl levulinate from biomass derived levulinic acid. This study demonstrates successful cost effective transformation of fly ash into environmentally benign catalyst. [Display omitted] • Waste coal fly ash (CFA) transformation into value added materials. • Synthesis of zeolites (Mordenite) from waste coal fly ash and their characterization. • Synthesis of n-butyl levulinate from levulinic acid using fly ash derived zeolites. • High conversion with selectivity towards n-butyl levulinate. • Proposed reaction mechanism for the synthesis of n-butyl levulinate. [ABSTRACT FROM AUTHOR]

Coke formation inside heterogeneous reactors is an important industrial problem that leads to reduced catalyst efficiency. However, this study aims to prove the benefits of coke build-up in improving catalyst performance. The formation and decomposition of coke on six different zeolite structures was studied. The dissociation kinetic model of the spent catalysts during the toluene alkylation with 1-heptene inside a stainless-steel autoclave reactor at different temperatures was carried out. Various techniques (XRD, XRF, TPO, CHNS and TGA-DTG) were used. It was found that the conversion and selectivity of the desired product were higher on the parent H-mordenite and the dealuminated H-beta catalysts with conversions of 85.3% and 84.67%, respectively, at a 360 min reaction time. This was attributed to the reduction of the ratio of hard:soft coke. It is confirmed that the decomposition activation energies of hard coke, 140.1–202.6 kJ/mol, are much higher energies than those of soft coke, 89.9–118.7 kJ/mol. It is also noted that the hypothesis of pore mouth catalysis is dominated by non-polyaromatic coke on the surface of the H-beta catalysts, while the hypothesis is dominated by polyaromatic coke on the surface of the H-mordenite catalysts. [Display omitted] • At different temperatures, the toluene alkylation reactions with 1-heptene were conducted. • Parents H-beta and H-mordenite Zeolites along with their modified samples were used as catalysts. • Influence of zeolite structural pores on type of accumulated coke, activity and selectivity. • Study of the decomposition of coke using multiple reaction kinetic models. [ABSTRACT FROM AUTHOR]

Hierarchical mordenite catalysts were prepared by HF and NH 4 F etching. Materials' zirconia modification was performed by incipient wetness impregnation in order to vary surface acidity type and strength. XRD, N 2 physisorption, solid-state NMR and UV–Vis spectroscopies were applied for characterization. Acidic properties of the obtained materials were investigated by TPD of adsorbed ammonia and FT-IR spectra of adsorbed pyridine. Catalytic performance was studied for the glycerol esterification with acetic acid. Zr increased reaction turnover activity compared to raw zeolite substrate due to abundant Brönsted and Lewis moiety presence. The demonstrated biomass valorization processes to bio-based platform chemicals are of interest, as they employ biodiesel production waste. [ABSTRACT FROM AUTHOR]

Copper-exchanged mordenite prepared by supercritical ion exchange (SCIE) and aqueous ion exchange (AIE) were investigated in stepwise conversion of methane to methanol. Increasing the oxygen activation temperature and methane reaction time enhances the methanol yield of copper-exchanged mordenite prepared by SCIE (Cu-MOR S). The reducibility of Cu-MOR S was compared with those of Cu-MOR A prepared by aqueous ion exchange (AIE) using H 2 -TPR. It was demonstrated for the first time that deconvoluted H 2 -TPR profile coupled with effects of Cu loading and oxygen activation temperature on methanol yield data can be used to distinguish the active Cu sites from inactive ones based on their reduction temperature. The copper species responsible for methane activation were found to be reduced below 150 °C by H 2 in both Cu-MOR S and Cu-MOR A. From the stoichiometry of the reaction of H 2 with Cu2+ species, the average number of copper atoms of active sites were calculated as 2.07 and 2.80 for Cu-MOR S and Cu-MOR A , respectively. Differences in structure of copper species caused by the synthesis routes were also detected by in-situ FTIR upon NO adsorption indicating a higher susceptibility of Cu-MOR S towards autoreduction. The results demonstrated the potential of TPR based methods to identify copper active sites and suggested the importance of site selective ion exchange in order to controllably synthesize active Cu species in zeolites. [Display omitted] • Cu-MOR S and CuMOR A prepared by SCIE and AIE were tested for SMTM. • A H 2 -TPR based technique was developed to identify and quantify the active sites. • Active Cu sites were reduced below 150 °C by H 2. • Active Cu/methanol ratio was 2.07 for Cu-MOR S and 2.8 for Cu-MOR A. • Ion exchange method affects the Cu speciation and the material autoreducibility. [ABSTRACT FROM AUTHOR]

The aim of this work was to carry out an experimental study along with kinetic and thermodynamic analysis for the toluene disproportionation reaction under actual industrial operating conditions. The toluene disproportionation reaction was carried out under pressurized hydrogen and over three different ZSM-5 based catalysts, namely, ZSM-5, 3%Mo on ZSM-5, and 3%Mo on ZSM-5/Mordenite. The influence of reaction temperature and catalyst composition on conversion and product distribution was investigated. A network of reversible reactions and elementary rate laws reflecting the product distribution, including xylene isomers and other products, were proposed and validated using the obtained experimental data. The thermodynamic parameters were estimated using a chemical process simulation package (Aspen HYSYS), while numerical and statistical methods were used to estimate the kinetic parameters. A notable agreement between the model predictions and the experimental data was obtained. The Mo-impregnated, mordenite-containing catalyst (3%Mo on ZSM-5/Mordenite) was found to be the most active catalyst, presumably due to the additional metallic-active sites that were readily accessible through the mordenite's large pores compared to the plain ZSM-5 catalyst. In addition, the most active catalyst was found to have the lowest activation energies and lead to conversions that were limited thermodynamically. [Display omitted] • Toluene disproportionation (TDP) was kinetically modeled and thermodynamically assessed • Depending on catalyst activity, TDP could be kinetically or thermodynamically limited • ZSM-5's catalytic activity was enhanced by incorporating Mo (3%) and mordenite (25%) • Spreadsheet software proved adequate for multiple reactions' kinetic parameters estimation • The kinetic parameters were determined using Euler and Reduced Gradient methods [ABSTRACT FROM AUTHOR]

Active gold catalysts for CO oxidation were obtained by the deposition–precipitation of gold on ZSM-5 and mordenite, both of them ion-exchanged with manganese. A strong promotion of Mn upon the activity of bimetallic Au/Mn catalysts was observed when compared with the monometallic Au–zeolites. In turn, when an in-situ reduction of the bimetallic catalysts was performed, a further increase in activity was observed. Characterizations suggested that smaller gold nanoparticles were stabilized in the bimetallic solids and that the reduction process caused a rearrangement of Au and Mn species on the catalyst surface. [ABSTRACT FROM AUTHOR]

The liquid-phase alkylation of benzene with 1-tetradecene was realized over dealuminated mordenites with different mesoporous surface areas and three different levels of acidity. The mordenite catalysts were characterized by N 2 -sorption, FTIR pyridine adsorption, and TPDA. The number of Brønsted acid sites decreases; however, it represents a higher proportion of the total acidity. Alkylation results demonstrated that the mordenite activity in alkylation accelerated with increasing mesoporous surface area in spite of the lower total acidity. This fact indicates that the accessibility of acid sites and the internal mass transport in mordenite channels play a significant role in liquid-phase alkylation of aromatics with 1-alkenes. [ABSTRACT FROM AUTHOR]

Abstract: Selective oxidation of alkenes with air to corresponding epoxides was performed over simple ion-exchanged Co-MOR and Co-5A. Among all transition metal ions-exchanged M-zeolites, both Co-MOR and Co-5A exhibited the highest activity at 363K. Notably, for the epoxidation of styrene, α-pinene, α-methyl styrene and cyclooctene, Co-MOR obtained higher conversions than Co-5A, in agreement with the difference of pore sizes of both zeolitic materials. Recycling and control tests showed high durability of Co-MOR as a heterogeneous catalyst in our catalytic system. [Copyright &y& Elsevier]

Abstract: Selective dealumination of mordenite by high-temperature steam treatment improved its stability in dimethyl ether carbonylation. Most of the framework Al species in the 12-membered ring channels of mordenite was removed while those in the 8-membered ring channels were retained. On the resulting mordenite catalyst, the formation rate of methyl acetate was only slightly decreased and maintained at 1.71mol (molH+)−1 h−1 at 15h. Temperature-programmed oxidation analyses on the used sample evidenced that the deposition of hard coke was effectively suppressed in the selectively dealuminated catalyst because of the reduced number of acidic sites in the 12-membered ring channels. [Copyright &y& Elsevier]

Abstract: A study of the lean NOx reduction activity with butane and toluene in the presence of water over bimetallic and monometallic Ag, Co exchanged on Na-mordenite catalysts was performed. The Ag–Co interactions were analyzed through X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) techniques. It is shown that the metal silver particles formed at low temperature during the TPR experiment improve the dissociation of hydrogen thus facilitating the reduction of Co2+ species. The incorporation of 3.2wt.% of silver to CoM catalyst, significantly improved the NOx to N2 conversion with butane, which reached 95% under wet conditions (2% H2O). However, this effect was not observed when toluene was the reducing agent. [Copyright &y& Elsevier]

Abstract: Microporous mordenite with a low Si/Al ratio was synthesized by using silicic acid powder as silica source under hydrothermal condition. By treating the mordenite with acid and base, mesoporous mordenite (M-Mor) was obtained, which was characterized by X-ray diffraction (XRD), N2 sorption experiments, and scanning electron microscopy (SEM). Based on the M-Mor material, iron-containing mesoporous mordenite (Fe-M-Mor) was prepared by ion-exchanged method. The benzylation of benzene by benzyl chloride showed that Fe-M-Mor was a highly active catalyst in this reaction and could be reused. These results indicate that Fe-M-Mor has potential applications in Friedel–Crafts alkylations, especially of large molecules. [Copyright &y& Elsevier]

Abstract: Sulfonic acid functionalised SBA-15 (SO3H-SBA-15), sulfated zirconia and beta, Y, ZSM-5 and mordenite zeolite catalysts have been applied for the dehydration of sugars to ethyl levulinate and ethyl-d-glucopyranoside (EDGP) using ethanol as solvent and reactant. The SO3H-SBA-15 catalyst showed a high catalytic activity for the selective conversion of fructose to ethyl levulinate (57%) and glucose to EDGP (80%) at 140°C, whereas the disaccharide sucrose yielded a significant amount of both products. The SO3H-SBA-15 catalysts were found to be highly active compared to the zeolites under identical reaction conditions. [Copyright &y& Elsevier]

Abstract: The combination of a Pd/CeO2 catalyst for in situ generation of CO, via methanol decomposition, with a copper mordenite methanol carbonylation catalyst has been shown to be a successful strategy for the development of a methanol-only halide-free route to acetic acid. There is a pronounced dependence upon reactor bed configuration. A stacked bed, in which the Pd/CeO2 decomposition catalyst is placed upstream of the Cu-MOR carbonylation catalyst, exhibits a much greater acetyls yield than a physical mixture of the two catalysts. [Copyright &y& Elsevier]

Abstract: Composite zeolite catalytic tubular membranes containing rhodium(0) and ruthenium(0) in and on alumina tubes were prepared using the hydrothermal synthesis method termed “multi in situ crystallization” (MISC). The membranes were tested in the partial oxidation of methane to investigate membrane activities. Transition metal-dispersed zeolitic catalytic tubular membranes exhibit a high catalytic surface area, large membrane surface area and high chemical and thermal stabilities. The applicability of these membranes to the partial oxidation reaction is demonstrated. [Copyright &y& Elsevier]

Abstract: A delaminated zeolite with Si/Al=29, obtained by swelling and ultrasonication of a laminar precursor of Nu-6(2), has been examined as a solid acid catalyst for the liquid phase cyclodehydration of xylose to furfural at 170°C, using a water–toluene biphasic reactor system. The final material, with a specific surface area about seven times higher than that for proton-exchanged Nu-6(2), gave a reaction rate about two times higher than that for H-Nu-6(2), and could be recycled several times without loss of performance or Al leaching. The furfural yield after 4h reaction was 47%, compared with 34% in the presence of an H-mordenite sample with Si/Al∼6. [Copyright &y& Elsevier]

Abstract: Bifunctional catalysts based on acidified Mordenite or ZSM-5 and platinum or palladium as metal function, were tested for n-pentane hydroisomerization. Two methods were used to introduce platinum: wetness impregnation and microemulsion; palladium was introduced via an organometallic complex. A lower catalytic activity was obtained for palladium catalyst in comparison with platinum samples which is explained by the lower activity of Pd in the dehydrogenation reaction step. Different catalytic behaviour of systems based on Mordenite and ZSM-5 was attributed to zeolite pore structure. The uncompleted removal of surfactant during calcination could explain the lower activity showed by catalysts prepared by microemulsion. [Copyright &y& Elsevier]

Adsorption of propionitrile (PrN), isobutironitrile (IBN) and pivalonitrile (PN) with H-MOR (Si/Al=10) has been investigated. The accessibility of IBN and, more, of PN are limited, unlike PrN. Terminal silanols (3745 cm−1), weakly acidic, are located, as Lewis sites, at the external crystal surface. Bridging hydroxy groups absorbing at 3588 cm−1 are inside the side pockets, those absorbing at 3605 cm−1 are in the main channels and those absorbing at 3609 cm−1 are at the intersection between side pockets and main channels. OH’s due to extra framework materials (3650 cm−1) are in the side pockets. [Copyright &y& Elsevier]

The effect of crystal size of HMOR from micro size to 50 nm, with the apparent similar acid site density, on catalytic performance for the dimethyl ether (DME) carbonylation was investigated. The crystal size of HMOR is sensitive to the deactivation rate of DME carbonylation reaction, and the higher stability around 200 nm can be achieved. The characterization studies reveal that the diffusions of MA product play a key role during the induction and deactivation period in DME carbonylation. These will be helpful for guiding the large-scale synthesis of mordenite zeolites catalysts with high efficiencies for DME carbonylation. [Display omitted] • The dependence of catalytic performance on the crystal size of HMOR from has been established. • The stability of DME carbonylation is sensitive to the crystal size of HMOR between 330 nm and 200 nm. • The diffusions of MA product play a key role on the induction and deactivation period in DME carbonylation. • HMOR around 200 nm was proposed for DME carbonylation from viewpoint of industrial practices. [ABSTRACT FROM AUTHOR]

Acidic mordenite zeolite was modified with various alkyimidazolium ions with different sizes via ion-exchange and applied as dimethyl ether (DME) carbonylation catalysts. Introducing 1, 3-dimethylimidazolium ions into zeolite can selectively remove the acid sites in 12-membered ring (MR) channels, significantly enhancing the stability and activity. Additionally, ion-exchange with organic ions was used to control the acid site distributions to separately investigate the DME carbonylation reaction in 8-MR and 12-MR channels. The reaction results indicated that the acid sites in 12-MR channels can concurrently catalyze the carbonylation and methanol-to-hydrocarbons (MTH) reactions, and MTH reactions seriously suppress the carbonylation activity in 8-MR channels. Unlabelled Image • Acid sites at the 12-membered-ring pores also catalyze dimethyl ether carbonylation • Methanol-to-hydrocarbons reactions can suppress the carbonylation reaction • Introducing 1, 3-dimethylimidazolium ions into mordenite enhances the staibility • The size of organic ions is the key factor governing the catalytic performance [ABSTRACT FROM AUTHOR]

Abstract: This communication presents the production of a mordenite film growth totally confined into 350μm wide microchannels on copper alloy plates for microreactor preparation. The growth is obtained in open channel configuration by secondary synthesis after 12h of treatment over this highly thermal conductivity support. The confined growth presents a high overall quality. It is crystalline, uniform, and adherent; it totally covers the microchannels surface and has 5μm. These properties are confirmed by XRD, SEM and EPMA characterizations. [Copyright &y& Elsevier]