Catalyst For Alkylation Research Articles

Pluronic F127-assisted partial decomposition of ammonium phosphomolybdate and its application as an efficient and recyclable catalyst for the alkylation of toluene with benzyl alcohol

The thermal decomposition of ammonium phosphomolybdate was adjusted by F127 to obtain an efficient and recyclable catalyst for liquid-phase alkylation.

Design of highly stable metal/ZSM-5 catalysts for the shape-selective alkylation of toluene with methanol to para-xylene

The co-existence of (Pt + Ni) effectively inhibits the formation of low-carbon olefins during the alkylation of toluene with methanol via the dehydrogenation of methanol to carbon oxides and also the hydrogenation of olefins to paraffins.

Elucidating Effect of Acid Strength on Isomerization Mechanisms of Butene Over Solid Acid Catalysts in C4 Alkylation

Elucidating Effect of Acid Strength on Isomerization Mechanisms of Butene Over Solid Acid Catalysts in C4 Alkylation

The Preparation of Zr-Containing Polymer as an Efficient Catalyst for Alkylation of Amines with Alcohols

The Preparation of Zr-Containing Polymer as an Efficient Catalyst for Alkylation of Amines with Alcohols

Synthesis of hierarchical nanocrystalline β zeolite as efficient catalyst for alkylation of benzene with benzyl alcohol.

To develop an efficient solid acid catalysts for the Friedel–Crafts alkylation reaction, especially for involving bulky molecules, the direct synthesis of hierarchical nanocrystalline β zeolites were achieved by using amphiphilic organosilane ([(CH3O)3SiC3H6N(CH3)2C18H37]Cl, TPOAC) as collaborative structure-directing agent (SDA). The growth evolution of β crystals and the influence of TPOAC/SiO2 molar ratio on the mesoporous structure, crystal size, and acidic properties of β zeolites were investigated and discussed in detail. The characterization results reveal that intracrystalline mesopores and intercrystalline mesopores/macropores via the stacking of β nanocrystals were generated over the hierarchical β zeolites. Moreover, most of the strong acid sites were well remained compared with the conventional microporous β zeolite. Consequently, the hierarchical nanocrystalline β zeolite synthesized under the optimized synthesis conditions shows improved specific catalytic activity of acid sites (turnover number, TON) in alkylation of benzene with benzyl alcohol, which can be attributed to the integrated balance of considerable mesoporosity, accessibility of the acid sites, and well-remained strong acid sites in the hierarchical β zeolite.

W Modified HY Zeolite as Catalyst for Alkylation of Aromatic

W Modified HY Zeolite as Catalyst for Alkylation of Aromatic

Characterization and Hydrogenation Removal of Acid-Soluble Oil in Ionic Liquid Catalysts for Isobutane Alkylation

Characterization and Hydrogenation Removal of Acid-Soluble Oil in Ionic Liquid Catalysts for Isobutane Alkylation

Shape-selective alkylation of benzene with ethylene over a core–shell ZSM-5@MCM-41 composite material

A series of ZSM-5@MCM-41 core–shell composite materials prepared via a multi-cycle-sol–gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene, in which both ethylbenzene and para-diethylbenzene ( p- DEB) are aimed as the target products. With multi-cycle-sol–gel coating, the external acid sites on the samples are gradually passivated by the inert MCM-41 shell. As a result, the shape selectivity to p- DEB is greatly enhanced. Nevertheless, the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity, which is a reason that core–shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene. In order to enhance the yield of p- DEB on ZSM-5@MCM-41, the reaction conditions at the fixed bed reactor including temperature, the molar rate of benzene to ethylene and GHSV, are also optimized.

Efficient synthesis of bis(indolyl)methanes by the alkylation of indoles with alcohols using heterogeneous CuFe2O4 catalyst

Bis(3-indolyl)methanes (BIM) are highly valuable and appear in the core structure of many natural products and pharmacologically active compounds (anticancer, anti-inflammatory, antiobesity, antimetastatic, antimicrobial, etc.). Herein, we have disclosed an air stable and highly efficient CuFe2O4 heterogeneous catalyst for alkylation of indoles with alcohols to give bis(3-indolyl)methanes in very good yields. The CuFe2O4 catalyst has been found to be magnetically recycled at least five times without losing significant catalytic activity.

A mechanistic periodic DFT study of CH, CO, and OH dissociations in methanol: M-doped carbon nanotubes (M=Pt, B, Al, N, P) versus Pt(100), Pt(110) and Pt(111) surfaces

• CO, CH, and OH dissociations in methanol are studied by using Pt(100), Pt(110), Pt(111), and doped CNT. • Dissociations are studied from both thermodynamics and kinetics points of view. • Theory shows that proposed SACs have less barrier energy for C−O dissociation compared to pure Pt surfaces. Periodic density functional theory is used to study adsorption and first step dissociation of methanol on M-doped carbon nanotubes (M = B, Al, Pt, N, and P) as a single atom catalyst (SAC). Data are compared with the adsorption and dissociation of methanol on Pt(100), Pt(110), and Pt(111). Only the first step of methanol dehydrogenation is investigated by considering three models of dissociations containing CH 3 + OH, CH 3 O + H, and CH 2 OH + H. The second model of dissociation is endothermic on all facets of Pt catalyst, but exothermic on B-, Al-, and Pt-doped carbon nanotube. The model of dissociation of CH 2 OH + H is more thermodynamically favorable on Pt(100), Pt(111), and Pt-doped carbon nanotube comparing to two other models. The most exothermic reaction belongs to the CH 3 + OH model on Al-doped carbon nanotube with -1.00 eV energy. Transition state calculations show that the barrier energy of C‒O dissociation on Al-doped carbon nanotube is 1.55 eV which is less than the barrier energies of C‒O dissociation on Pt(100), Pt(110), and Pt(111) which are 2.29, 2.45, and 1.96 eV. This shows that Al-doped carbon nanotube is a good candidate for alkylation catalyst. On the other hand B-doped carbon nanotube is a good non-metal catalyst for hydrogen production through O‒H dissociation.

Effect of Binder Content on the Properties of Nanocrystalline Zeolite BEA-based Catalysts for Benzene Alkylation with Propylene

Effect of Binder Content on the Properties of Nanocrystalline Zeolite BEA-based Catalysts for Benzene Alkylation with Propylene

The shape selectivity of zeolites in isobutane alkylation: An investigation using CBMC and MD simulations

The adsorption and diffusion behaviors of C8 isomers and C9 component as main products of the isobutane alkylation catalyzed by zeolites with different topologies were investigated using configurational bias Monte Carlo (CBMC) and MD simulations in this work. The adsorption capacity of zeolites at 353 K and 2.0 MPa relies on their pore volume with the order of FAU > BEA > LTL > MOR. The diffusion coefficient of C8 and C9 molecules increases with the decrease of loading and the increase of temperature, and the more compact molecules diffuse slower than the slimmer ones at low loadings while quicker at higher loadings. It was found that for zeolites, small adsorption heat of C8 isomers, or large molecular diffusion coefficient would correspond to a high selectivity of target alkylates. Particularly, BEA zeolite with large RPLD/LCD shows high reaction selectivity, rendering it a good candidate catalyst for C4 alkylation.

Study on the reaction strategy of directional alkylation fulfilled by controlling the adsorption pose of benzene and methanol in space with Ru/HZSM-5

BackgroundThe alkylation of benzene with methanol is an important synthetic method that is widely used in various chemical production processes. However, obtaining a high selectivity for xylene and annihilating the MTO side reaction remain challenges.ResultsIn this work, a Ru/HZSM-5 catalyst was prepared using ZSM-5 as the precursor by a chemical precipitation method. Both XRD and TEM confirmed that Ru nanoparticles were evenly dispersed on the surface of the ZSM-5. The catalytic performance of benzene alkylation with methanol on the Ru/HZSM-5 catalyst was investigated. The results showed that the Ru/HZSM-5 catalyst could completely annihilate the MTO side reaction with a high conversion efficiency of benzene and selectivity for xylene, which resulted from the large gap between the transgression energy value of Ru and the ionization potential value of benzene, and the acidity of the catalyst changed greatly.ConclusionThese findings may offer not only a new and efficient multifunctional catalyst for benzene alkylation but also fundamental insight into the catalytic mechanism of the Ru/HZSM-5 catalyst.

Computation-guided descriptor for efficient zeolite catalysts screening in C4 alkylation process

Zeolites as the environmentally friendly catalysts for C4 alkylation suffer from rapid deactivation in commercial application. In this work, the intrinsic descriptor (i.e., the i-butane/1-butene ratio in micropores) for catalyst deactivation was proposed by configurational-bias Grand Canonical Monte Carlo (CB-GCMC) calculations. It is found that pore structural topology affects the competitive adsorption between i-butane and 1-butene due to distinct structure of the two adsorbates. The i-butane/1-butene ratios in the pore decreased in the order: BEA > FAU > MOR > MFI. In other words, 3D interconnecting BEA channels formed by 12-membered rings with ordered pore configuration were suggested to have higher i-butane/1-butene ratio, because i-butane has better spatial matching with 12-membered rings on basis of the analysis of the size. Notably, experimental deactivation rate is inversely proportional to calculated i-butane/1-butene ratio inside microproes with good linear correlation. This descriptor for deactivation offers a promising avenue for rational screening of more efficient zeolite catalysts for C4 alkylation.

High Catalytic Activity of a Seawater Fly Ash Based Zeolite for Phenol Alkylation

Zeolites have been used as catalysts and high cation-exchange materials because of their suitable structure, uniform pore size and high cation-exchange capacity. In this paper, type X zeolites synthesized from fly ash were employed as substrates for developing catalysts with improved performance. With the aim to determine potential application of synthetic products in catalysis, zeolites (with different values of BET surface area) were tested in the gas-phase as basic catalysts for phenol alkylation using diethyl carbonate as an innovative alkylating agents. The results indicate that the newly-formed zeolites are very selective for the O‑ethylation of phenol also at higher temperature. The catalytic activity of the zeolites synthesized from fly ash gives high yields, is clean, cost effective, environmentally friendly which make the fly ash-based zeolites efficient catalysts and alternatives for industrial applications.

A New Preparation Method for the Alkylation Catalysts of Aromatic Compounds Based on Immobilized AlCl3

A New Preparation Method for the Alkylation Catalysts of Aromatic Compounds Based on Immobilized AlCl3

Facile access to bis(indolyl)methanes by copper-catalysed alkylation of indoles using alcohols under air

Bis(3-indolyl)methanes (BIM) are important and present in the structure of many alkaloid and bioactive compounds (anti-inflammatory, anticancer, antiobesity, antimicrobial, etc.). Herein, we have reported an air stable and convenient Cu(OAc)2 catalyst for alkylation of indoles with alcohols to give bis(3-indolyl)methanes in very good yields.

Quaternary ammonium cellulose promoted synthesis of hollow nano-sized ZSM-5 zeolite as stable catalyst for benzene alkylation with ethanol

Catalytic alkylation of benzene with ethanol has been considered as a sustainable alternative for producing ethylbenzene/diethylbenzene. This paper reports the promoted synthesis of hollow nano-sized (20–80 nm) ZSM-5 zeolite as excellent yet durable catalyst of benzene alkylation, which is achieved by adding N-methyl-2-pyrrolidone (NMP) and quaternary ammonium cationic hydroxyethyl cellulose (JR-400) in its synthesis gel during the synthesis. It is revealed by the ESI–MS and TEM characterization that the NMP promotes the dissolution–recrystallization of the ZSM-5 and a hollow structure is generated during the process. The JR-400 as special promoter further favors the formation of ordered nano-zeolite grain and suitable microstructure, confirmed by the molecular dynamic modeling and characterization. That action corporately contributed to the hollow nano-sized ZSM-5 zeolite that provided hierarchical porous structure and mild acid centers, as evidenced by the 129Xe and 1H NMR spectra. The obtained hollow zeolite ZSM-5 then exhibits enhanced catalytic activities and selectivity for benzene alkylation. Moreover, it also displays an extremely superior stability (deactivation rate constant, −0.06%/h) in the catalysis of benzene alkylation with ethanol. This behavior is attributed to its hierarchical porous structure (namely less diffusion resistance) and mild acid centers, which is beneficial to moderate the carbon deposition and then the catalyst deactivation. Those research results urge the JR-400-promoted synthesis as a facile strategy for the hollow nano-sized ZSM-5 with enhanced catalytic performance during the benzene alkylation with the ethanol.

Characterizing the electronic structure of ionic liquid/benzene catalysts for the isobutane alkylation

When a small amount of benzene was introduced into the chloroaluminate ionic liquid (IL), the IL − alkylation can produce premium alkylation gasoline. In order to deepen our understanding of IL − alkylation in general, the electronic properties of [BMIm][AlCl4]/benzene/reactant system were analyzed by the ADCH charge analysis, DOS analysis, frontier molecular orbital analysis, non − covalent interactions (NCI), and energy decomposition analysis (EDA). ADCH analysis reveals that benzene could markedly affect the charge transfer of alkanes and chloroaluminate anions, which weakened the super−acidity of the IL. Frontier molecular orbital analysis shows that the IL system has a significant decrease of H − Lgap, and it increases the sensitivity of the reactants. The anchoring effect of [BMIm]+ cation was observed in the DOS spectra, which enhanced stabilization of the IL structure. NCI analysis shows that π − H bonds could be formed between benzene and the IL. It is believed that better alkylation performance of IL/benzene system is due to these weak interactions.

Synthesis and performance of piperidinium‐based ionic liquids as catalyst for alkylation of p‐xylene with 1‐hexadecene

Piperidinium‐based ionic liquids (ILs) were synthesized under mild conditions by coordinating N‐alkyl‐N‐methylpiperidinium bromide ([Pip1,x]Br) with anhydrous AlCl3. The weak basicity of N‐methylpiperidine had little impact on downstream problems from proton impurities and catalyst poisoning. The results of Fourier transform infrared (FT‐IR), electrospray ionization mass spectrometry (ESI‐MS), and nuclear magnetic resonance (27Al NMR) confirmed that the active components in [Pip1,x]Br‐2AlCl3 (χ = 0.67) were [Al3Cl9Br]− and [Al2Cl6Br]−. Besides, the reaction performance of [Pip1,8]Br‐2AlCl3 under different conditions was carried out by single‐factor experiment and further confirmed by orthogonal experimental method. Among these reaction conditions, the optimal combination was the reaction temperature of 40°C, ILs/O molar ratio of 0.2:1, px/O molar ratio of 12:1, and the reaction time of 30 min. Furthermore, [Pip1,8]Br‐2AlCl3 had excellent stability and can be recycled 14 times. It was the high‐efficiency catalytic activity and prominent recyclability that made continuous industrial production possible.