ZSM-5 Molecular Sieve Research Articles

Template-free synthesis of silicon‑aluminum intergrowth molecular sieves using industrial residues without pretreatments for producing 5-hydroxymethylfurfural (5-HMF)

As a silicon‑aluminum solid waste in the preparation of fluid catalytic cracking (FCC) catalysts, residues (named as FCCR) are directly employed as synthesis raw materials without any pretreatments. An eco-friendly and template-free route is proposed to prepare ZSM-5/mordenite intergrowth molecular sieves using FCCR via a microwave assisted hydrothermal method. ZSM-5/mordenite intergrowth molecular sieves with controllable porosity and acidity are obtained. The proportion of ZSM-5 or mordenite molecular sieves is regulated by optimizing synthesis conditions (e.g., amount of seed, heating temperature/ duration, alkalinity, and SiO2/Al2O3). ZSM-5/mordenite intergrowth molecular sieves exhibit catalytic performance in the dehydration reaction of glucose to prepare 5-hydroxymethylfurfural (5-HMF). The in-situ FTIR approach proves a dehydration route “glucose→fructose→5-HMF” under the synergistic effect of BrØnsted and Lewis acid sites. These results are important for the disposal of FCCR and eco-friendly synthesis of molecular sieves.

A Molecular-Sieve Electrolyte Membrane enables Separator-Free Zinc Batteries with Ultralong Cycle Life.

The poor stability of the zinc-metal anode is a main bottleneck for practical application of aqueous zinc-ion batteries. Herein, a series of molecular sieves with various channel sizes are investigated as an electrolyte host to regulate the ionic environment of Zn2+ on the surface of the zinc anode and to realize separator-free batteries. Based on the ZSM-5 molecular sieve, a solid-liquid mixed electrolyte membrane is constructed to uniformize the transport of zinc ions and foster dendrite-free Zn deposition. Side reactions can also be suppressed through tailoring the solvation sheath and restraining the activity of water molecules in electrolyte. A V2 O5 ||ZSM-5||Zn full cell shows significantly enhanced performance compared to cells using glass fiber separator. Specifically, it exhibits a high specific capacity of 300 mAh g-1 , and a capacity retention of 98.67% after 1000 cycles and 82.67% after 3000 cycles at 1 A g-1 . It is attested that zeolites (ZSM-5, H-β, and Bate) with channel sizes of 5-7 Å result in best cycle stability. Given the low cost and recyclability of the ZSM and its potent function, this work may further lower the cost and boost the industrial application of AZIBs.

Preparation and study of hydrophobic silica@ZSM-5 nanocomposites for multi-functional coating

In this study, the easy moisture absorption of molecular sieves was addressed by a two-step surface hydrophobic modification process. First, the hydrolysis-condensation of tetraethoxysilane (TEOS) was performed on the pre-treated ZSM-5 zeolite powders to fabricate silica encapsulated ZSM-5 (SiO2@ZSM-5) molecular sieves. Second, hydrogen-containing silicone oil (HCSO) was grafted on the surface of SiO2@ZSM-5 molecular sieves to prepare hydrogen-containing silicone oil modified silica@ZSM-5 (HCSO-m-SiO2@ZSM-5) nanocomposites. After modification, the BET specific surface area of HCSO-m-SiO2@ZSM-5 nanocomposite was reduced from 275 to 69 m2 g−1, the pore volume was decreased from 0.27 to 0.05 cm3 g−1, and the average pore diameter was decreased from 4.6 to 2.6 nm. Then, the HCSO-m-SiO2@ZSM-5 nanocomposites were used as fillers to endow epoxy resin (EPR) coatings with hydrophobicity. The water contact angle of as-prepared HCSO-m-SiO2@ZSM-5/EPR composite coatings reached up to 148° at 30 wt% filler content. Electrochemical analysis shows that the corrosion potential (Ecorr) of composite coatings was positively shifted from −1.060 to −0.433 V and the corrosion current (Icorr) was reduced from 9.0791 × 10−5 to 2.4433 × 10−6 A/cm2 with the increase of filler content from 0 to 30 wt%, demonstrating their enhanced anti-corrosion property. Furthermore, the dielectric, light-shielding and mechanical properties were investigated. The results indicate that the composite coatings perform multifunctions of good hydrophobicity, dielectric performance, anti-corrosion, light-shielding efficiency and mechanical properties, which may have great potential in electronics applications.

Fabrication of BTA-loaded mesoporous silica-encapsulated ZSM-5 molecular sieve for enhancing anti-corrosion performance of waterborne epoxy coatings

Anti-corrosion coatings have been widely applied to protect metals against corrosion attacks. To improve the corrosive resistance, it is an effective way to employ porous materials loaded with corrosion inhibitors as fillers of coatings. One of the critical challenges is to advance the inhibitor loading capability of porous fillers. In this study, the mesoporous silica encapsulation is introduced on the ZSM-5 molecular sieves through the hydrolysis-condensation of tetraethyl orthosilicate (TEOS), followed by calcinated for removing the residual templates. The porous SiO2@ZSM-5 particles are used as micro-nano containers to load corrosion inhibitor benzotriazole (BTA). The morphologies, structures and BTA releasing behaviors are thoroughly investigated. Subsequently, the as-prepared BTA-SiO2@ZSM-5 particles serve as fillers for waterborne epoxy resin (WER) to fabricate BTA-SiO2@ZSM-5/WER composite coatings with long-term anti-corrosion property. The corrosive resistance behavior and mechanism are emphatically tested and analyzed. The results demonstrate that the introduction of mesoporous silica on the ZSM-5 molecular sieves significantly increases the specific surface area and pore volume, which is highly beneficial for improving the BTA loading capability of fillers as well as the anti-corrosion performance of coatings. Moreover, the great dielectric, mechanical and UV light-shielding properties of the composite coatings are confirmed. This study presents an effective and practical route for fabricating long-term anti-corrosive composite coatings.

Graphene oxide promotes V-Cu-Ce-ZSM-5 to catalyze SO2 and NO at low temperature: performance and mechanism.

A catalyst (V-Cu-Ce-ZSM-5) was explored to simultaneously remove the SO2 and NOx from flue gas by use of the ZSM-5 molecular sieve as the carrier, V and Cu as the active components, and Ce as the additive in low temperature of 150 °C. The performance of V-Cu-Ce-ZSM-5 was evaluated for the oxidation of NO and SO2 before and after the addition of graphene oxide (GO). The results showed that V-Cu-Ce-ZSM-5@GO0.5 had the best performance at a reaction temperature of 150 °C, and the oxidation efficiency of SO2 and NO was 94.60% and 83.64%, respectively. The multiple structural characterizations (BET, SEM, Raman, XRD, and XPS) revealed that the loading of V and Cu with the additive Ce expanded the specific surface area and pore volume of ZSM-5, provided more adsorption sites for SO2 and NO, and had good desulfurization and denitration activity. The addition of GO further improved the dispersibility of active components and auxiliaries, increased the number of active sites in the reaction process, and significantly improved catalytic activity.

Amine-free synthesis of fly ash based ZSM-5 via interzeolite transformation with related investigation of mechanism

Fly ash is a solid waste consisted of SiO 2 , Al 2 O 3 , CaO, Fe 3 O 4 and trace amounts of heavy metal (Hg and Cd), therefore, their disposal could pose some threats to the environment. In this paper, the interzeolite transformation of NaA to ZSM-5 was explored as a low-cost and high value-added green process, where fly ash was resource utilized, and the conventionally high-cost silicalite-1 seeds and high-contamination organic amine were not required. Firstly, fly ash was activated with NaOH at high temperature, followed by the alkali-dissolving purification to remove the impurities. Then, purified fly ash was utilized to synthesize NaA at 110 °C for 12 h, and the transformations of NaA to ZSM-5 were conducted and the process parameters were optimized such as crystallization temperature, duration time, the content of additives such as ethanol or sodium chloride and the pretreatment of NaA, and so on. The results showed that the introduction of a trace amounts of NaCl or EtOH could greatly facilitate the growth of ZSM-5, and the high crystalline ZSM-5 molecular sieves were successfully obtained at 160 °C for 36 h with the comparable textual properties to the commercial ZSM-5. Finally, an assembly mechanism of MFI framework in the interzeolite transformation of NaA to ZSM-5 was proposed. • Fly ash was alkali-melting activated followed by the alkali-dissolving purification. • High-pure and high-active fly ash was used as raw materials to synthesize NaA zeolite. • Amine-free synthesis of ZSM-5 was conducted via interzeolite transformation of NaA assisted with NaCl or EtOH. • A transcrystal mechanism was proposed of synergistic structural guiding effects of NaA and four-coordinate Na + .

Removal of Elemental Mercury from Simulated Flue Gas by a Copper-Based ZSM-5 Molecular Sieve

A series of Cu-ZSM-5 molecular sieve adsorbents were prepared by the impregnation method. The experimental results revealed that the mercury removal efficiency of the 2.5 wt% CuCl2-ZSM-5 can reach up to 99%. Furthermore, both the crystal type and pore size distribution of the ZSM-5 molecular sieve remain the same after the process of copper-based active materials impregnated modification, and its specific surface area decreases as the load increases. Importantly, the surface of ZSM-5 modified by CuCl2 equips many more Cu-O functional groups, which are beneficial to the catalytic oxidation of mercury and can even oxidize Hg0 to Hg2+. The adsorption process strictly follows the Mars–Maessen reaction mechanism.

Novel iron-supported ZSM-5 molecular sieve remove arsenic from wastewater by heterogeneous nucleation with pH limit breaking

Molecular sieves have also been used for arsenic adsorption in recent years because of their special structure. In order to solve the problem of arsenic pollution in drinking water and/or industrial wastewater, ZSM-5/Fe adsorbent was prepared by loading iron on ZSM-5 molecular sieve. It is also used as an excellent adsorbent for removing arsenic and other heavy metal ions from industrial wastewater. At room temperature, the concentration of arsenic was reduced from 100 mg/L to 0.006 mg/L after the solution pH was adjusted to the range of weak acid to weak base (4–10) and 0.5 g of ZSM-5/Fe adsorbent was added for reacting 2 h. The adsorption capacity reached 40.00 mg/g, the adsorption efficiency reached 99.99%, reaching the national standard of drinking water. Adsorption thermodynamics, kinetics and isotherms showed that the adsorption mechanism of arsenic is heterogeneous nucleation adsorption (including electrostatic attraction and chemical precipitation). Moreover, ZSM-5/Fe adsorbent can adjust pH spontaneously by using non-skeleton Si–Al phase to achieve effective adsorption from weak acid to weak base. At the same time, ZSM-5/Fe adsorbent showed good reusability and stability in five cycles. This study provides an important idea for the application of ZSM-5 molecular sieve in many fields and the efficient removal of arsenic from drinking water and industrial wastewater.

Adsorption Properties of ZSM-5 Molecular Sieve for Perfluoroisobutyronitrile Mixtures and Its Fluorocarbon Decomposition Products

Perfluoroisobutyronitrile (C4F7N), an environment-friendly insulating gas, has excellent insulating properties and has the potential to be used in gas-insulated equipment when mixed with CO2. Selecting suitable adsorption materials to adsorb the decomposition products of the C4F7N mixture can ensure the safe and stable operation of the gas-insulated equipment and the personal safety of the operators in the electric power industry. The adsorption characteristics of the ZSM-5 molecular sieve on C4F7N and its five fluorocarbon decomposition products were investigated by adsorption experiments. The results show that the ZSM-5 molecular sieve has a certain adsorption effect on six fluorocarbon gases; the adsorption performance of C3F6 and C3F8 are the best, with an adsorption efficiency over 85%, while the concentration of CO2 and C4F7N is affected by the ZSM-5 molecular sieve. At the same time, the paper based on the Metropolis Monte Carlo simulation of Materials Studio software found that the ZSM-5 molecular sieve has the strongest adsorption effect on C4F7N molecules and the weakest adsorption effect on CO2 molecules. The stronger the polarity of the gas molecule, the more obvious the adsorption effect of molecular sieve structure on it. As a result, the ZSM-5 molecular sieve could be used in tail gas purification of insulated equipment, as well as to provide solutions for the development and production of protective equipment.

An environmental friendly self-healing coating with Silane/Ce-ZSM-5 zeolite structure for corrosion protection of aluminum alloy

This paper investigated the preparation of new environmental, pH stimulation response nanocontainer enhanced, self-healing, and efficient anti-corrosion coating for aluminum alloy protection. Silane/Ce-ZSM-5 coating with improved morphology was successfully synthesized on aluminum alloy surface, through the new proposed “hydrothermal crystallization - ion exchange - self-assembled seed growth - hot pressing” technology, in which ZSM-5 molecular sieve was served as pH stimulation response nanocontainer. The corrosion resistance and self-healing ability of the coating in 3.5 wt% NaCl solution were further investigated by the combined analysis of SEM, EIS, LEIS, ICP-MS characterization and 3D microscopic observation. The experimental results showed that the prepared silane-Ce-ZSM-5 coatings exhibited excellent corrosion protection and self-healing ability, which was attributed to the pH stimulation release of corrosion inhibitor Ce3+ when the coatings were damaged. The ZSM-5 zeolites generated Ce(OH)3 or CeO2 precipitates to gradually fill the aluminum alloy defects, thus forming a dense protective layer and inhibiting the corrosion activity.

Preparation of core-shell ZSM-5@Beta molecular sieve and catalytic alkylation to 2,6-Dimethylnaphthalene

ZSM-5@Beta core-shell molecular sieve was prepared by dynamic hydrothermal synthesis method using ZSM-5 adhered Beta seed crystals as the core phase, and polydiallyl dimethyl ammonium chloride (PDDA) was used as a coupling agent to adhere Beta seed crystals on the surface of ZSM-5. The structure and physical properties of composite molecular sieves were characterized by XRD, N2 adsorption-desorption, SEM, TEM, ICP, NH3-TPD and Py-FTIR. The catalytic performance of composite molecular sieves for alkylation of 2-methylnaphthalene (2-MN) with methanol was investigated. The results showed that ZSM-5@Beta composite molecular sieve prepared by this method had a core-shell structure, and the particle size was about 500 nm. Compared with mechanically mixed binary molecular sieve, core-shell molecular sieve had higher specific surface area and external surface area, lower acid strength and stronger acid center density. Through the construction of core-shell interface and hierarchical porous, the catalytic activity was improved by shell phase Beta molecular sieve with 12-membered ring channel, and the catalytic selectivity was improved by core phase ZSM-5 molecular sieve with 10-membered ring channel in the alkylation reaction of 2-MN with methanol. The 2,6-/2,7-DMN ratio in the products reached 1.35, and the yield of 2,6-DMN reached 4.29%.

Establishment of Deep-Eutectic-Solvent-Assisted Matrix Solid-Phase Dispersion Extraction for the Determination of Four Flavonoids in Scutellariae Radix Based on the Concept of Quality by Design.

Sample preparation is the most crucial step in analytical schemes. Micro-matrix solid-phase dispersion, as a method for microextraction of analytes, has prevailed recently for its low sample and extraction solvent consumption. However, small amounts of adsorbent or sample, or a short extraction time, always bring uncertainty to the result when using this method. The aim was to develop a simple and reliable method of deep-eutectic-solvent-assisted ultrasonic-synchronized matrix solid-phase dispersion microextraction for the analysis of four flavonoids in Scutellariae Radix based on the concept of quality by design. The ZSM-5 molecular sieve was used as a new adsorbent in the micro-matrix solid-phase dispersion process. Single-factor and Box-Behnken designs were used to construct the design space. Verification of the experiment demonstrated that the design space is robust. Under optimal conditions, all analytes showed good linearity (R2 > 0.999), high reproducibility (RSD < 2.24%) and stability (RSD < 2.87%), and satisfactory recoveries (95.90-102.31%), which indicated that the established method is reliable and reproducible. Moreover, it has been successfully applied to determine the flavonoids in nine batches of Scutellariae Radix. The results indicate a great potential for analyzing complicated samples especially with small amount and helping to promote the quality control of the sample preparation process for traditional Chinese medicines. A systematic approach using a facile deep-eutectic-solvent-assisted ultrasonic-synchronized matrix solid-phase dispersion extraction coupled with HPLC for the analysis of flavonoids in Scutellariae Radix has been developed based on the concept of quality by design.

Green Synthesis and Application of ZSM-5 Zeolite

A ZSM-5 molecular sieve composite with a wide pore prepared by the solid phase in-situ synthesis method and fluid catalytic cracking, and an FCC catalyst additive prepared by the same ZSM-5 molecular sieve for increasing the amount of light olefin yield were investigated. The samples were characterized by XRD, N2 adsorption/desorption, SEM, and NH3-TPD, respectively. The results showed that the structure of the ZSM-5 molecular sieve composite prepared by solid phase in-situ synthesis method was pure MFI-type zeolite material. The crystallinity of ZSM-5 molecular sieve was 59.8 wt%. The synthesized ZSM-5 molecular sieve had more acid content and a wide-pore structure. The average pore size was 5.9 nm, and BET specific surface area and micropore specific surface area of sample were 213 m2 g–1 and 124 m2 g–1, respectively. The evaluated results indicated that the FCC catalyst additive had good selectivity for LPG, propylene, and butene, increasing propylene and butene yields by 2.28 wt% and 2.15 wt%, respectively, as well as had better heavy oil cracking capability and coke selectivity.

Effects of Ni substitution on active oxygen species and electronic interactions over La0.8Ce0.2MnO3/mesoporous ZSM-5 for oxidizing C6H14

Based on fly ash, mesoporous ZSM-5 (MZ) molecular sieves were prepared using a combination of hydrothermal treatment and fractional calcination. The La0.8Ce0.2Mn1-yNiyO3/MZ(y≤0.5) obtained using an impregnation load method was studied regarding the hexane oxidation, which was chosen as the probe molecule of volatile organic compounds (VOCs) at 120−390 °C. Additionally, the physicochemical characteristics of the catalysts were characterized by XRD, SEM, TEM, BET, XPS, NH3-TPD, H2-TPR and O2-TPD to investigate the electronic interactions over La0.8Ce0.2MnO3/MZ with Ni substitution and the active oxygen species, the main influence factors and the reaction mechanism for hexane oxidation. The results showed that there was a strong electronic interaction between LaMnO3 and MZ, and Ni substitution at Mn sites in La0.8Ce0.2MnO3 could promote the electronic transfer among the La, Ce, Ni, Mn and MZ, which could improve the low temperature reducibility, as well as facilitate the migration and distribution of the surface oxygen species. Additionally, La0.8Ce0.2Mn0.5Ni0.5O3/MZ demonstrated a higher catalytic activity for hexane oxidation due to its higher migration capacity of the outer lattice oxygen species (O2−), indicating that the outer lattice oxygen species as the active oxygen species were the main factor for hexane oxidation corresponding to the Mars-Van Krevelen (MvK) reaction mechanism. However, the specific surface area, the low temperature reducibility of high valence state cation ions (Mn4+ and/or Ni4+/Ni3+) and the surface acidity could be key but not main factors in hexane oxidation. Furthermore, La0.8Ce0.2Mn1-yNiyO3/MZ (y≤0.5) showed good catalytic stability, coke deposition resistance and H2O resistance. Based on the results of in situ DRIFTS and GC–MS, two reaction routes of hexane oxidation could be proposed over the La0.8Ce0.2Mn1-yNiyO3/MZ (y≤0.5) catalysts in air, therein, the decomposition of carbonate species could be one of the main rate- controlling steps at ≤ 320 °C.

Active oxygen species and oxidation mechanism over Ce-doped LaMn0.8Ni0.2O3/hierarchical ZSM-5 in pentanal oxidation

Hierarchical ZSM-5 (HZ) molecular sieves based on fly ash were synthesized using a method combining water heat treatment with step-by-step calcination. The coupling catalysts between La1−xCexMn0.8Ni0.2O3 (x ≤ 0.5) perovskites and HZ were prepared through the impregnation method, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption, X-ray photoelectron spectroscopy (XPS), NH3-temperature programmed desoprtion (NH3-TPD), H2-temperature programmed reduction (H2-TPR) and O2-TPD techniques and investigated regarding pentanal oxidation at 120−390 °C to explore the effects of Ce doping on the catalytic activity and the active oxygen species of the coupling catalysts, meanwhile, the reaction mechanism and pathway of pentanal oxidation were also studied. The results reveal that Ce substitution at La sites can change the electronic interactions between all the elements and promote the electronic transfer among La, Ce, Ni, Mn and HZ, influencing directly the physicochemical characteristics of the catalysts. Moreover, the amount and transfer ability of surface adsorbed oxygen (O2– and O–) regarded as the reactive oxygen species and the low temperature reducibility are the main influence factors in pentanal oxidation. Additionally, La0.8Ce0.2Mn0.8Ni0.2O3/HZ exhibits the best catalytic activity and deep oxidation capacity as well as a better water resistance due to its larger amount of surface adsorbed oxygen species and higher low temperature reducibility. What’s more, appropriate Ce substitution can significantly enhance the amount of O2– ions, which can distinctly enhance the catalytic activity of the catalyst, and moderate acid strength and appropriate acid amount can also facilitate the improvement of the pentanal oxidation activity. It is found that there is a synergic catalytic effect between surface acidity and redox ability of the catalyst. According to the in situ DRIFTS and GC/MS analyses, pentanal can be oxidized gradually to CO2 and H2O by the surface oxygen species with the form of adsorption in air following the Langmuir–Hinshelwood (L-H) reaction mechanism. Two reaction pathways for the pentanal oxidation process are proposed, and the conversion of the formates to carbonates may be one of the main rate-determining steps.

Seed-assisted synthesis and characterization of nano and micron ZSM-5 molecular sieves in template-free system

A novel and environment friendly seed-assisted one-step and segmented methods were employed to synthesize micro-scale, submicron-scale and nano-scale ZSM-5 molecular sieves in template-free system. The products were characterized by XRD, SEM, FT-IR, TGA/DTA and N2 adsorption-desorption analysis, respectively. The results showed that micro-scale ZSM-5 were prepared by one-step method via ZSM-5 seeds with uniform and regular pupal-like shape and particles size of 5 ​× ​3 ​μm, submicron-scale ZSM-5 of 250~500 ​nm and nano-scale ZSM-5 of 25~40 ​nm were successfully obtained with stacking mesopores via silicate-1 seeds by one-step crystallization method and segmented crystallization method, respectively. Furthermore, the crystallization time could be shortened to 6 ​h by silicate-1 seeds assisted low-high temperature segmented method.

Promoted catalytic behavior over γ-Al2O3 composited with ZSM-5 for crude methanol conversion to dimethyl ether

γ-Al2O3 was composited with ZSM-5 molecular sieve to improve its catalytic performance and hydrothermal stability during the conversion of crude methanol into dimethyl ether (DME). When prepared by a liquid-phase coating chemical compounding, the ZSM-5/γ-Al2O3 composite catalyst reached an excellent methanol conversion of 91.9% and DME selectivity of 100%. The DME yield was increased by about 13% compared to only using γ-Al2O3. Partial desiliconization and dealumination of the ZSM-5 molecular sieve effectively reduced the surface acid center strength and increased the mesoporous ratio. The special composite phase interface effectively decreased surface charge density of γ-Al2O3 and formed the B (Brønsted) - L (Lewis) synergistic active centers. All these factors contribute to improving the catalytic performance, hydrothermal stability and resistance to deactivation of ZSM-5/γ-Al2O3 during the conversion of crude methanol to DME.

Synthesis of Mesoporous ZSM-5 Zeolite and Its Adsorption Properties for VOCs

A composite template method was used to synthesize a ZSM-5 molecular sieve containing intracrystalline mesopores. In this paper, the charge ratio and the amount of mesoporous template have been set as variables. The synthesized samples were characterized through XRD, TEM and BET and its absorption performance of toluene has been qualitatively analyzed. The results showed that the synthesis of ZSM-5 structure required a suitable charge ratio and the amount of composite templating agent. The specific surface area of molecular sieve with ZSM-5 structure can be up to 499 m2/g, which charge ratio was 0.8. Besides, the maximum of adsorption amount of static adsorption and adsorption rate of dynamic adsorption were 265 mg/g and 16.75% respectively.

Fabrication of high-silica Cu/ZSM-5 with confinement encapsulated Cu-based active species for NH3-SCR

For high-temperature gas-phase reactions in the presence of steam such as the selective catalytic conversion of NOx from mobile sources, the deactivation of catalysts often occur because of their poor hydrothermal stability. Herein, we successfully prepared a high-silica Cu/ZSM-5-PAD catalyst based on an effectively induced polymer (polyacrylamide) assisted deposition (PAD) strategy. The obtained catalyst exhibited excellent catalytic performance for NH3-SCR in terms of activity, anti-hydrothermal aging and poison-resistant abilities. This excellent catalytic performance could be correlated with the encapsulation and confinement dispersion of Cu-based active species within the ZSM-5 molecular sieve channels, which dramatically optimized the catalytic properties and structural stability of the solid.

Effect of Fe-modified ZSM-5 catalyst during microwave assisted pyrolysis of Mengdong lignite for the oil production

Microwave catalytic pyrolysis of Mengdong lignite by Fe-modified ZSM-5 catalysts was studied. The effects of pyrolysis method and the ZSM-5 molecular sieves loading different amounts of Fe2O3 on the total tar yield were investigated. The results show that the microwave heating technology could effectively improve the yield of lignite pyrolysis tar; In the conventional pyrolysis, the total yield of raw coal pyrolysis oil was 2.19%. When the Fe2O3 loading was 5%, the catalyst had the best effect with the yield of 3.56%, and the increase rate was 62.56%; Under microwave condition, the pyrolysis oil yield of raw coal is 6.43%. When the Fe2O3 loading increased from 0 to 10%, the total yield of tar increased from 7.02% to 9.47%. When the Fe2O3 loading was 10%, the catalyst had the best effect with the increase rate of 62.56%.