Effect of Hydrohalogenation of Metal/Zeolite Catalysts for Cyclohexene Hydroconversion ‐Part 3‐ Pd/H‐ZSM‐5 Catalysts

Cyclohexene (CHE) hydroconversion was performed in a flow reactor at atmospheric pressure and temperatures of 50–400 °C using: Pd/H‐ZSM‐5, Pd/H‐ZSM‐5(HCl), and Pd/H‐ZSM‐5(HF) catalysts. These catalysts were characterized for acid site strength distribution via NH₃ TPD, Pd dispersion via H₂ chemisorption, TPR via reduction of the metal oxide in the catalysts and XRD for tracing crystallinity The hydroconversion steps proceeded as follows: CHE → Cyclohexane (CHA); CHE → Methylcyclopentenes (MCPEs) → Methylcyclopentane (MCPA); CHE → Cyclohexadienes (CHDEs) → Benzene → Alkylbenzenes; CHE and others → Hydrocrackedproducts. The overall hydroconversion of CHE was achieved in the catalyst order: Pd/H‐ZSM‐5 > Pd/H‐ZSM‐5(HF) > Pd/H‐ZSM‐5(HCl). CHE hydrogenation step was the major reaction at low temperatures which significantly inhibited via HCl treatment, but slightly enhanced via HF treatment. At medium temperatures, on all catalysts, isomerisation to MCPEs and MCPA increase to a maximum then a decline with a further increase of temperature. The overall isomerisation of CHE was highest on the untreated catalyst. During the higher temperature range, dehydrogenation, alkylation and hydrocracking were increased with temperature. Dehydrogenation of CHE always yielded larger amounts of 1,3‐CHDE than 1,4‐CHDE. These cyclohexadienes were produced in the catalyst order: Pd/H‐ZSM‐5(HF) > Pd/H‐ZSM‐5(HCl) > Pd/H‐ZSM‐5. In general, benzene alkylation to toluene exceeded that of xylenes, indicating that the second methylation is more difficult than the first. However, the catalytic activities for benzene and toluene production were in the order: Pd/H‐ZSM‐5 » Pd/H‐ZSM‐5(HCl) > Pd/H‐ZSM‐5(HF), whereas for xylenes production, Pd/H‐ZSM‐5 » Pd/H‐ZSM‐5(HF) > Pd/H‐ZSM‐5(HCl). Intrapore diffusion plays an important role during the dehydrogenation reactions as well as during the interconversion of individual aromatic hydrocarbons.     

Cyclohexene Reactivity Using Catalysts Containing Pt,Re and PtRe Supported on Na‐ and H‐Mordenite

The reactivity of cyclohexene (CHE) over catalysts containing 0.3 wt% Pt, 0.3 wt% Re or 0.3 wt% Pt + 0.3 wt% Re supported on Na‐ and H‐mordenite has been studied in an atmospheric flow‐type reactor at a temperature range of 100–400 °C, using a flow of hydrogen (20 cm³/min). The catalysts were characterized for acid sites strength‐distribution, using desorption of ammonia in DSC. The acidity of H‐mordenite (HM) is attributed to strong acid sites, whereas the acidity of Na‐mordenite (NaM) is due to weak acid sites which are not involved in the catalytic reaction under study. The catalysts containing HM enhance the reactivity of CHE for isomorization reactions. However, the reactivity of CHE on NaM catalysts enhances only the hydrogenation and dehydrogenation reactions. Pt/HM is the most selective catalyst for isomerization of CHE, whereas Pt/NaM and PtRe/NaM catalysts are the most selective for hydrogenation and dehydrogenation reactions, respectively. The hydroisomorization of CHE seems to depend only on the acidity of the catalysts, whereas both hydrogenation and dehydrogenation reactions were controlled by metallic function of the catalysts.     

Electro‐oxidation of Methanol and Ethanol Catalyzed by Pt/ZSM‐5/C

Direct alcohol fuel cells are a promising source of future energy generation for small and portable devices. Platinum is considered the best catalyst for electro‐oxidation of alcohols in fuel cells but the major hurdles with platinum catalysts are high cost of platinum as well as low selectivity, slow reaction kinetics and carbonaceous poisoning associated with platinum. This particular research reports electro‐oxidation of methanol and ethanol over platinum electrodeposited on ZSM‐5 without any carbon additive. From the cyclic voltammetry and chronoamperometry, linear sweep voltammetry, tafel plot and multiple scan analyses, it is found that Pt/ZSM‐5/C electrodes can catalyze electro‐oxidation of methanol and ethanol with higher efficiency. ZSM‐5 supports the formation of smaller sized platinum nanoparticles in a dispersed manner on the zeolite support and thus increases the active surface area of the metal for catalytic activity. It favors adsorption of alcohol molecules on the modified electrode surface and thus increases the diffusion process. It also stabilizes the modified electrodes.     

Phosphatation of Zeolite H‐ZSM‐5: A Combined Microscopy and Spectroscopy Study

A variety of phosphated zeolite H‐ZSM‐5 samples are investigated by using a combination of Fourier transfer infrared (FTIR) spectroscopy, single pulse ²⁷Al, ²⁹Si, ³¹P, ¹H‐³¹P cross polarization (CP), ²⁷Al‐³¹P CP, and ²⁷Al 3Q magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, scanning transmission X‐ray microscopy (STXM) and N₂ physisorption. This approach leads to insights into the physicochemical processes that take place during phosphatation. Direct phosphatation of H‐ZSM‐5 promotes zeolite aggregation, as phosphorus does not penetrate deep into the zeolite material and is mostly found on and close to the outer surface of the zeolite, acting as a glue. Phosphatation of pre‐steamed H‐ZSM‐5 gives rise to the formation of a crystalline tridymite AlPO₄ phase, which is found in the mesopores of dealuminated H‐ZSM‐5. Framework aluminum species interacting with phosphorus are not affected by hydrothermal treatment. Dealuminated H‐ZSM‐5, containing AlPO₄, retains relatively more framework Al atoms and acid sites during hydrothermal treatment than directly phosphated H‐ZSM‐5.     

A Brief Catalyst Study on Direct Methane Conversion Using a Dielectric Barrier Discharge

A series of metal catalysts was used for methane conversion to higher hydrocarbons and hydrogen in a dielectric barrier discharge. The main goal of this study is to identify the metal catalyst components which can influence the reactions in room‐temperature plasma conditions. The catalysts supported by γ‐Al₂O₃ and zeolite (ZSM 5x) were prepared by the incipient wetness method with solutions containing the metal ions of the second component. Among the catalysts tested, only Pt and Fe catalysts showed a unique result of catalytic reaction in a reactor bed packed with glass beads.     

Enthalpy and Entropy Barriers Explain the Effects of Topology on the Kinetics of Zeolite‐Catalyzed Reactions

The methylation of ethene, propene, and trans‐2‐butene on zeolites H‐ZSM‐58 (DDR), H‐ZSM‐22 (TON), and H‐ZSM‐5 (MFI) is studied to elucidate the particular influence of topology on the kinetics of zeolite‐catalyzed reactions. H‐ZSM‐58 and H‐ZSM‐22 are found to display overall lower methylation rates compared to H‐ZSM‐5 and also different trends in methylation rates with increasing alkene size. These variations may be rationalized based on a decomposition of the free‐energy barriers into enthalpic and entropic contributions, which reveals that the lower methylation rates on H‐ZSM‐58 and H‐ZSM‐22 have virtually opposite reasons. On H‐ZSM‐58, the lower methylation rates are caused by higher enthalpy barriers, owing to inefficient stabilization of the reaction intermediates in the large cage‐like pores. On the other hand, on H‐ZSM‐22, the methylation rates mostly suffer from higher entropy barriers, because excessive entropy losses are incurred inside the narrow‐channel structure. These results show that the kinetics of crucial elementary steps hinge on the balance between proper stabilization of the reaction intermediates inside the zeolite pores and the resulting entropy losses. These fundamental insights into their inner workings are indispensable for ultimately selecting or designing better zeolite catalysts.     

Large Zeolite H‐ZSM‐5 Crystals as Models for the Methanol‐to‐Hydrocarbons Process: Bridging the Gap between Single‐Particle Examination and Bulk Catalyst Analysis

The catalytic, deactivation, and regeneration characteristics of large coffin‐shaped H‐ZSM‐5 crystals were investigated during the methanol‐to‐hydrocarbons (MTH) reaction at 350 and 500 °C. Online gas‐phase effluent analysis and examination of retained material thereof were used to explore the bulk properties of large coffin‐shaped zeolite H‐ZSM‐5 crystals in a fixed‐bed reactor to introduce them as model catalysts for the MTH reaction. These findings were related to observations made at the individual particle level by using polarization‐dependent UV‐visible microspectroscopy and mass spectrometric techniques after reaction in an in situ microspectroscopy reaction cell. Excellent agreement between the spectroscopic measurements and the analysis of hydrocarbon deposits by means of retained hydrocarbon analysis and time‐of‐flight secondary‐ion mass spectrometry of spent catalyst materials was observed. The obtained data reveal a shift towards more condensed coke deposits on the outer zeolite surface at higher reaction temperatures. Zeolites in the fixed‐bed reactor setup underwent more coke deposition than those reacted in the in situ microspectroscopy reaction cell. Regeneration studies of the large zeolite crystals were performed by oxidation in O₂/inert gas mixtures at 550 °C. UV‐visible microspectroscopic measurements using the oligomerization of styrene derivatives as probe reaction indicated that the fraction of strong acid sites decreased during regeneration. This change was accompanied by a slight decrease in the initial conversion obtained after regeneration. H‐ZSM‐5 deactivated more rapidly at higher reaction temperature.     

NH3-SCR反应中Fe-ZSM-5的Fe物种分布和酸性位对其水热稳定性及抗硫和抗碳氢性能的影响

以Na+型和H+型ZSM-5为载体制备了Fe-ZSM-5催化剂并用于氨选择性催化还原(NH3-SCR)氮氧化物. Fe-H-ZSM-5在新鲜时和750 oC含10%水的空气中老化后,其SCR活性均优于Fe-Na-ZSM-5.表征结果显示, Fe-H-ZSM-5和Fe-Na-ZSM-5的Fe物种分布和酸性位有所不同.高温水热老化后Fe-H-ZSM-5分子筛骨架的脱铝较Fe-Na-ZSM-5严重.水和硫的存在对Fe-H-ZSM-5和Fe-Na-ZSM-5的SCR活性的影响相似,即降低了低温活性,略提高了高温活性. Fe-Na-ZSM-5表现出比Fe-H-ZSM-5更好的抗碳氢中毒性能.这两种催化剂的SO2和碳氢中毒是可逆的.     

Coupling of Methanol and Carbon Monoxide over H‐ZSM‐5 to Form Aromatics

The conversion of methanol into aromatics over unmodified H‐ZSM‐5 zeolite is generally not high because the hydrogen transfer reaction results in alkane formation. Now circa 80 % aromatics selectivity for the coupling reaction of methanol and carbon monoxide over H‐ZSM‐5 is reported. Carbonyl compounds and methyl‐2‐cyclopenten‐1‐ones (MCPOs), which were detected in the products and catalysts, respectively, are considered as intermediates. The latter species can be synthesized from the former species and olefins. ¹³C isotope tracing and ¹³C liquid‐state NMR results confirmed that the carbon atoms of CO molecules were incorporated into MCPOs and aromatic rings. A new aromatization mechanism that involves the formation of the above intermediates and co‐occurs with a dramatically decreased hydrogen transfer reaction is proposed. A portion of the carbons in CO molecules are incorporated into aromatic, which is of great significance for industrial applications.     

铂和 HF 掺杂的 H-ZSM-5 分子筛催化甲苯与甲醇烷基化反应

 Toluene was alkylated with methanol in a flow type reactor at temperatures between 300 and 500 °C using H-ZSM-5 zeolite, 0.2%Pt/H-ZSM-5 and hydrofluorinated 0.2%Pt/H-ZSM-5 with HF concentrations of 1.0%, 2.0%, 3.0%, or 4.0%. Pt primarily enhances toluene conversion, total xylenes production, and p-xylene relative to its thermodynamic equilibrium. As the concentration of HF increases from 1.0% to 3.0%, the catalyst activity increases because of the increase in the number of acid sites and their strength. Additionally, the surface area and Pt dispersion also increases. An advantage of increased HF doping is that the formation of voluminous trimethylbenzene (TMB) byproducts is inhibited. However, at a HF concentration of 4.0%, Al and Si are partially leached and then deposited mostly in the wider catalytic pores. This was determined by evaluating the pore volume distribution and we determined that reactivity inhibition was ob-viously present and was due to diffusion restriction.     

载体性质对Pt催化剂H2选择催化还原NOx活性和选择性的影响

研究了Pt/MgO, Pt/γ-Al2O3, Pt/ZrO2和Pt/HZSM-5催化剂上H2选择催化还原消除NOx(H2-SCR)反应。结果发现, H2-SCR活性和N2生成选择性受催化剂中Pt的金属性以及载体的氮氧化物吸附能力影响很大。 HZSM-5的表面酸性使载体对NOx吸附能力较小,使担载Pt以较高的金属性存在,从而导致Pt/HZSM-5催化剂的高活性和高选择性。相反, Pt/MgO和Pt/γ-Al2O3催化剂较差的活性和选择性可归因于其载体的碱性表面、催化剂中Pt较低的金属性以及载体对氮氧化物较大的吸附能力。结合反应的原位红外光谱结果可以认为,在Pt/载体界面处亚硝酸根/硝酸根物种被还原为N2或N2O,取决于该处参与反应的活性H与这些含氮物种的相对数目。     

One-step conversion of n-butane to isobutene over H-beta supported Pt and Pt,M (M = Cu, In, Sn) catalysts: An investigation on the role of the second metal

The one-step transformation of n-butane to isobutene was studied over H-beta zeolite supported Pt and Pt,M (M = Cu, In, Sn) catalysts. Catalytic performance of monometallic Pt/H-beta samples resulted to be affected by the support acidity, a lower number of acid sites leading to higher iso- and n-butenes selectivities and lower by-products formation. Addition of Cu, In or Sn to Pt enhanced both isobutene and n-butenes selectivities, which were in the order: Pt,In > Pt,Sn  Pt,Cu > Pt. All Pt,M samples exhibited also a higher stability than the corresponding monometallic Pt samples, the sequence of deactivation rates being: Pt > In,Pt > Cu,Pt ≈ Sn,Pt. On the basis of characterization results it was stated that the addition of Cu, In or Sn to Pt affects the n-butane dehydroisomerization modifying both the surface structure of Pt clusters and the support acidity. In particular the observed order of isobutene selectivity was related to the degree of Pt–M interaction leading to a dilution of Pt clusters, which inhibits hydrogenolysis reactions and enhances dehydrogenation processes. The decrease in the number of acid sites caused by addition of the second metal was instead accounted for the improved resistance to deactivation of Pt,M catalysts.     

Reversible Nature of Coke Formation on Mo/ZSM‐5 Methane Dehydroaromatization Catalysts

Non‐oxidative dehydroaromatization of methane over Mo/ZSM‐5 zeolite catalysts is a promising reaction for the direct conversion of abundant natural gas into liquid aromatics. Rapid coking deactivation hinders the practical implementation of this technology. Herein, we show that catalyst productivity can be improved by nearly an order of magnitude by raising the reaction pressure to 15 bar. The beneficial effect of pressure was found for different Mo/ZSM‐5 catalysts and a wide range of reaction temperatures and space velocities. High‐pressure operando X‐ray absorption spectroscopy demonstrated that the structure of the active Mo‐phase was not affected by operation at elevated pressure. Isotope labeling experiments, supported by mass‐spectrometry and ¹³C nuclear magnetic resonance spectroscopy, indicated the reversible nature of coke formation. The improved performance can be attributed to faster coke hydrogenation at increased pressure, overall resulting in a lower coke selectivity and better utilization of the zeolite micropore space.     

Effects of Coke Deposits on the Catalytic Performance of Large Zeolite H‐ZSM‐5 Crystals during Alcohol‐to‐Hydrocarbon Reactions as Investigated by a Combination of Optical Spectroscopy and Microscopy

The catalytic activity of large zeolite H‐ZSM‐5 crystals in methanol (MTO) and ethanol‐to‐olefins (ETO) conversions was investigated and, using operando UV/Vis measurements, the catalytic activity and deactivation was correlated with the formation of coke. These findings were related to in situ single crystal UV/Vis and confocal fluorescence micro‐spectroscopy, allowing the observation of the spatiotemporal formation of intermediates and coke species during the MTO and ETO conversions. It was observed that rapid deactivation at elevated temperatures was due to the fast formation of aromatics at the periphery of the H‐ZSM‐5 crystals, which are transformed into more poly‐aromatic coke species at the external surface, preventing the diffusion of reactants and products into and out of the H‐ZSM‐5 crystal. Furthermore, we were able to correlate the operando UV/Vis spectroscopy results observed during catalytic testing with the single crystal in situ results.     

PtSnNa/SUZ-4:丙烷脱氢反应的高效催化剂

丙烷脱氢制丙烯是优化利用炼厂气和油田伴生气资源的一条重要途径.随着丙烯需求量的逐步增加,丙烷脱氢制丙烯日益受到重视.负载型PtSn/γ-Al2O3催化剂具有优良的丙烷脱氢活性和选择性,但在高温、低氢压的反应条件下,催化剂易积炭而失活.近年来,选用了微孔分子筛如ZSM-5和介孔分子筛如SBA-15和MCM-41作为PtSn催化剂的载体,结果表明,具有规整孔道结构的负载型PtSn/分子筛催化剂的丙烷脱氢反应稳定性明显优于PtSn/γ-Al2O3催化剂.SUZ-4分子筛与ZSM-5分子筛结构相似且孔径相当,所不同的是ZSM-5由十元环交叉孔道组成,而SUZ-4由十元环和八元环孔道垂直相交组成.我们用微型催化反应装置结合XRD、BET比表面积和孔体积测试、NH3吸附-程序升温脱附(NH3-TPD)、氢化学吸附、热重分析(TG)、H2程序升温还原(H2-TPR)和程序升温氧化(TPO)等多种物理化学手段研究了负载型PtSnNa/SUZ-4和PtSnNa/ZSM-5催化剂的结构和丙烷脱氢反应性能,以及这两种催化剂在丙烷脱氢反应中催化性能差异的原因.实验结果显示,在丙烷脱氢反应中,负载型PtSnNa/SUZ-4催化剂上丙烯选择性和反应稳定性明显优于PtSnNa/ZSM-5催化剂,说明载体一定程度上会影响催化剂上丙烷脱氢反应性能.XRD,BET比表面积和孔体积测试等表征手段结果表明,SUZ-4和ZSM-5的孔体积和比表面积比较接近,载体的结构又类似,且两者的积碳量也相近,故载体的基本性质和积碳量的差异不是引起催化剂性能差异的原因.NH3-TPD结果表明,H-SUZ-4的酸强度明显强于H-ZSM-5.由于浸渍法制备负载型PtSn催化剂所用前体为具有强酸性的混合溶液(H2PtCl6+SnCl4),存在于SUZ-4分子筛孔道内表面的强酸中心不利于上述前体与SUZ-4分子筛孔道内表面结合.ZSM-5分子筛孔道内表面比较弱的强酸中心,促进了催化剂前体在ZSM-5分子筛孔道内表面的分散与结合.和ZSM-5为载体的催化剂相比,PtSnNa/SUZ-4上Pt粒子大部分分散在载体的外表面,从而金属上的积碳不易引起催化剂的失活.故多孔材料上Pt的分布是影响催化活性差异的主要原因.为进一步证明多孔材料上Pt的分布是影响催化活性差异的主要原因,我们通过二苯并噻吩预处理催化剂的手段证明Pt粒子在分子筛孔内外的分布情况.由于二苯并噻吩的尺寸比较大(0.8 nm)不能进入到分子筛的孔道内(SUZ-4:0.56 nm,ZSM-5:0.56 nm),所以载体孔道外的部分Pt会被二苯并噻吩预处理而失去活性,而孔道内的Pt不会因为预处理仍具有催化活性.实验结果表明,PtSnNa/SUZ-4经过二苯并噻吩预处理后,催化活性大大降低;而PtSnNa/ZSM-5经过二苯并噻吩预处理后,催化活性几乎没有变化.说明PtSnNa/SUZ-4上Pt粒子大部分分散在载体的外表面,从而金属上的积碳不易引起催化剂的失活.     

Pt Nanoparticles Supported on Nitrogen‐Doped‐Carbon‐Decorated CeO2 for Base‐Free Aerobic Oxidation of 5‐Hydroxymethylfurfural

Currently, the base‐free aerobic oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to produce 2,5‐furandicarboxylic acid (FDCA) is attracting intense interest due to its prospects for the green, sustainable, and promising production of biomass‐based aromatic polymers. Herein, we have developed a new Pt catalyst supported on nitrogen‐doped‐carbon‐decorated CeO₂ (NC‐CeO₂) for the aerobic oxidation of HMF in water without the addition of any homogeneous base. It was demonstrated that the small‐sized Pt particles could be well dispersed on the surface of the hybrid NC‐CeO₂ support, and the activity of the supported Pt catalyst depended strongly on the surface structure and properties of the catalysts. The as‐fabricated Pt/NC‐CeO₂ catalyst, with abundant surface defects, enhanced basicity, and favorable electron‐deficient metallic Pt species, enabled an almost 100 % yield of FDCA in water with molecular oxygen (0.4 MPa) at 110 °C for 8 h without the addition of any homogeneous base, which is indicative of exceptional catalytic performance. Furthermore, this Pt/NC‐CeO₂ catalyst also showed good stability and reusability owing to strong metal–support interactions. An understanding of the role of surface structural defects and basicity of the hybrid NC‐CeO₂ support provides a basis for the rational design of high‐performance and stable supported metal catalysts with practical applications in various transformations of biomass‐derived compounds.     

Modeling of monolayer adsorption of hydrogen on ZSM‐5 zeolite by lattice density functional theory

The adsorption isotherms of hydrogen on microporous zeolite ZSM‐5, at supercritical conditions, have been modeled using the monolayer lattice density functional theory (LDFT) models, where the simple cubic lattice, face‐centered cubic lattice, body‐centered cubic lattice and tetragonal lattice structures are assumed for the arrangements of the adsorption sites inside pores based on the size and shape of the zeolite. The results indicate that the monolayer LDFT models appear to be effective in describing hydrogen adsorption on zeolite ZSM‐5 at supercritical conditions, and the calculated adsorption isotherms agree well with the experimental isotherms measured previously. The layer density of adsorbed phase is presented versus the bulk density and temperature. It is found that the densities of adsorbed phase on adsorbent surface are much higher than the bulk density for temperature range under study. However, in the core region, the layer densities are close to the bulk density. The monolayer adsorption is suitable for hydrogen on ZSM‐5 zeolite. Copyright © 2013 John Wiley & Sons, Ltd.     

Characterization of the Structure and Catalytic Activity of Pt/Sepiolite Catalysts

Four catalysts containing 1% w/w Pt deposited on various sepiolite supports were prepared. Two natural sepiolites and another two obtained by acid treatment of one of them were used. Both the sepiolites used as metal supports and the catalysts were characterized for structure and surface properties, using (1)H and (29)Si MAS NMR spectroscopy, and (29)Si CP/MAS NMR spectroscopy, in addition to hydrogen, pyridine, and CO(2) chemisorption measurements. The activity of the catalysts in the hydrogenation of benzene to cyclohexane and the dehydrogenation of cyclohexane to benzene was examined and the catalyst supported on the natural sepiolite called Pangel was found to be the most active of all. Copyright 2000 Academic Press.     

Direct Detection of Supramolecular Reaction Centers in the Methanol‐to‐Olefins Conversion over Zeolite H‐ZSM‐5 by 13C–27Al Solid‐State NMR Spectroscopy

Hydrocarbon‐pool chemistry is important in methanol to olefins (MTO) conversion on acidic zeolite catalysts. The hydrocarbon‐pool (HP) species, such as methylbenzenes and cyclic carbocations, confined in zeolite channels during the reaction are essential in determining the reaction pathway. Herein, we experimentally demonstrate the formation of supramolecular reaction centers composed of organic hydrocarbon species and the inorganic zeolite framework in H‐ZSM‐5 zeolite by advanced ¹³C–²⁷Al double‐resonance solid‐state NMR spectroscopy. Methylbenzenes and cyclic carbocations located near Brønsted acid/base sites form the supramolecular reaction centers in the zeolite channel. The internuclear spatial interaction/proximity between the ¹³C nuclei (associated with HP species) and the ²⁷Al nuclei (associated with Brønsted acid/base sites) determines the reactivity of the HP species. The closer the HP species are to the zeolite framework Al, the higher their reactivity in the MTO reaction.     

Ordered Mesoporous ZSM‐5 Employing an Imidazolium‐Based Ionic Liquid

Hierarchically porous ZSM‐5 was achieved by using a simple bottom‐up strategy combining zeolite seeds with imidazolium‐based ionic liquids. The bimodal ZSM‐5 with hexagonal arranged mesopores (3 nm) shows important activity in the acid catalysis of bulky compounds relative to conventional ZSM‐5.