Isomerization Of N-pentane Research Articles

OPTIMIZATION OF THE OPERATION OF AN ISOMERIZATION INSTALLATION FOR LIGHT PETROL FRACTIONS

The interest in this process lies in the fact that it has great value since low-octane components are used as raw materials - the n fraction. temperature – 62°С and catalytic reforming raffinates. This raw material contains mainly pentane and hexane fractions. This raw material, as well as fractions С5 and С6 obtained from a gas fractionation unit (GFU), and a central gas fractionation unit (CGFU), are isomerized in a hydrogen environment in the presence of a catalyst. Hydrocarbons with a relatively high octane number are obtained. When isomerizing the pentane fraction, a product with a higher octane number is obtained. Isomerization of n-pentane is of interest not only for the oil refining industry, but also for the petrochemical industry, since isopentane can be converted by dehydrogenation into isoprene, a raw material for rubber. The article conducted a study on the selection of the optimal catalyst for the light gasoline fraction isomerization unit located at the Atyrau Oil Refinery. The catalytic activity of the catalyst samples was assessed in a laboratory flow-type installation. Determination of the mass fraction of С2-С5 hydrocarbons in С5 hydrocarbon fractions (in raw materials and catalyst) was carried out by a method based on the separation of mixture components by gas-liquid chromatography. The components leaving the chromatographic column were detected using a thermal conductivity detector. The calculation of the mass fractions of components was carried out using the normalization method, taking into account correction factors. The minimum concentration of C2-С5 hydrocarbons, determined by the method used, is 0.01-0.05% wt.

Optimizing hydrogen-driven n-pentane isomerization over Pt-doped fibrous ZSM-5

This study focuses on developing and optimizing Pt-doped fibrous ZSM-5 catalysts for n-pentane hydroisomerization. The catalysts demonstrated improved Pt dispersion and surface area through comprehensive characterization, particularly in Pt/HFZSM-5. Catalytic evaluations revealed that Pt/HFZSM-5 exhibited remarkable hydroisomerization performance (91.9 % of conversion), surpassing commercial ZSM-5, attributed to the enhancement in physicochemical attributes like high surface area, moderate acid sites and active Pt dispersion. Notably, under optimized conditions (reaction temperature: 323.6 °C, treatment temperature: 453.7 °C, F/W ratio: 498.7 mL/g.min), Pt/HFZSM-5 achieved an impressive 92.6 % isomerization yield, signifying a substantial enhancement in catalytic activity. Mechanistic insights highlighted the pivotal role of acid sites along with hydrogen activation in hydroisomerization. The utilization of statistical modeling, response surface analysis, and experimental validation underscored the accuracy of the predictive model and its alignment with the observed outcomes (with 2.1 % variance). This work contributes to developing high-performance hydroisomerization catalysts and advances understanding of the underlying reaction mechanisms.

A novel synthesis of highly active and highly stable non-noble-nickel-modified persulfated Al2O3@ZrO2 core-shell catalysts for n-pentane isomerization

The non-noble metal modified sulfated zirconia was found easy to deactivate. Herein, highly active and highly stable non-noble core-shell Ni-S2O82−/Al2O3@ZrO2 catalysts (Ni-SA@Z-x, x = Al content in wt%) have been successfully prepared and investigated for n-pentane isomerization. The results showed that the core-shell Ni-SA@Z-30 provided a sustained high isopentane yield (63.1%) with little or no deactivation within 5000 min at a mild reaction pressure of 2.0 MPa, which can be attributed to the following factors: (i) carbon deposition was greatly suppressed by the large pore size and huge pore volume; (ii) the loss of sulfur entities was suppressed because the small and highly dispersed tetragonal ZrO2 particles can bond with the S species strongly; (iii) strong Brønsted acidity can be maintained well after the isomerization. The pore structures and acid nature of the core-shell Ni-SA@Z-x are entirely different from those of the normal structure Ni-S2O82−/ZrO2-Al2O3, even though the Al content and the compositions of the individual components are the same. The Al2O3 cores endow the catalysts with high internal surface area and high mechanical strength. Meanwhile, the ZrO2 shell, which consists of more and smaller tetragonal ZrO2 particles because of the large surface area of the Al2O3 core, promotes the formation of more stable sulfur species and stronger binding sites.

Role of Fe and Cr on the Structure and Activity of Pt/SO4-ZrO2 Used as Catalysts in n-pentane Isomerization

A Pt supported sulfated zirconia catalyst (SZ/Pt) was promoted by Fe and Cr via impregnation and co-participation methods. Firstly, the sulfated zirconia catalyst was evaluated to study its crystalline structure with different sulfuric acid ratios of 2:1, 5:1, 10:1, and 15:1. The catalyst appeared completely in the tetragonal phase at all acid ratios; except for 5:1. The state of the prepared catalyst was investigated by XRD, MAP, BET, TPD, FTIR, and TPR analyses. Incorporating Fe and Cr by impregnation method increases the surface area and acidity. In spite of increasing the acidity by loading Cr on SZ/Pt, the catalyst activity (conversion) decreases. Therefore, in this work increased inactivity is ascribed to the oxidative dehydrogenation activation. Among the prepared catalysts, the catalyst prepared by incorporating Fe and Cr by impregnation method (SZ/Fe-Cr-Pt) is the best catalyst in terms of catalytic activity. This sample increases the conversion 2.7 times compared with SZ/Pt.

Isomerization of Alkanes over Ionic Liquids Supported on SBA-15

Exploring the catalytic efficiency of ionic liquid supported on mesoporous material as heterogeneous organ catalysts for example, 1-Ethyl-3-methylimidazolium triflate and 1-ethyl-3-methylimidazolium chloride + AlCl3 (different ratio) immobilized on SBA-15 that contains 0.5% platinum, with regard to isomerization of n-pentane and n-hexane, along with commercial light naphtha feed conversion reactions. The prepared materials were characterized by several instrumental methods, which include temperature-programmed desorption to evaluate acid strength. The reactions were performed in a fixed-bed stainless steel reactor having high pressure by the down-flow method. This valuable novel isomerization reaction was strongly influenced by many key parameters, for instance, temperature, pressure, weight hourly space velocity, and flow rate of H2, which are discussed in detail. The Pt/EMIM-AlCl4(1:1)20/SBA-15 ionic liquid catalyst showed superior catalytic performance out of the four-catalyst system examined toward the above reactions, which is undoubtedly due to its significant turnover frequencies values of 8.6 s–1 and 8.5 s–1 and specific reaction rates values of 8.01 × 10–4 mol g–1 s–1 and 8.00 × 10–4 mol g–1 s–1 for n-pentane and n-hexane correspondingly. The order of catalytic activity is Pt/EMIM-AlCl4(1:1)20/SBA-15 > Pt-EMIM-Tf/SBA-15 > Pt/EMIM-Al2Cl7(1:2)20/SBA-15 > Pt-EMIM-Al2Cl7(1:2)30/SBA-15.

Preparation of Pt-ZSM-5 zeolite membrane catalysts for the isomerization of linear alkane

A ZSM-5 supported membrane was synthesized by secondary growth method. The Pt-ZSM5 membrane was prepared by impregnation method. The membrane was characterized by single gas permeation step at room temperature. The isomerization of n-pentane was chosen as a probe reaction for evaluating the catalytic performance of the membrane. In particular, the effect of the space velocity and the time on stream were considered. After the catalytic tests, the membrane was characterized by SEM, EDX and XRD. N2 permeance for the membrane, after calcination, was equal to 2.9 × 10-7 mol/m2.s.Pa indicating a coverage of the larger support pores by the zeolite crystals. This results was also confirmed by the SEM investigation. In addition, XRD analysis showed as the ZSM-5 was the desired zeolite-type. During the catalytic tests, it was observed a decrease of the nC5 conversion and an increase of the iC5 selectivity with WHSV. The nC5 conversion was decreased from 2.5 to less than 0.5, with an enhancement in weight hourly space velocity (WHSV), while the selectivity increases from 30 to over 70. On the other hand, it's conversion on catalyst enhanced from 10% to approximately 38%, with an increase in the reaction temperature from 250 to 450°C.

Thermodynamic Analysis on Isomerization of n-Pentane to Isopentane

Thermodynamic Analysis on Isomerization of n-Pentane to Isopentane

Influence of sulfating method on La–Ni–S2O82–/ZrO2–Al2O3 solid superacid catalyst for n-pentane isomerization

La–Ni–S2O82–/ZrO2–Al2O3 catalysts were successfully prepared by two different methods of sulfate impregnation, and the physico-chemical properties of the catalysts were characterized by X-ray diffraction, Brunauer–Emmett–Teller analysis, Fourier transform infrared spectroscopy, pyridine adsorption–infrared spectroscopy, and X-ray photoelectron spectroscopy techniques. Catalytic activities were evaluated in a fixed-bed flow reactor using n-pentane isomerization as the probe reaction. Compared with catalyst La–Ni–S2O82–/ZrO2–Al2O3-I, prepared by the traditional impregnation method, the catalyst La–Ni–S2O82–/ZrO2–Al2O3-W, prepared by the incipient-wetness impregnation method, possessed higher pore volume, pore size, sulfur content, and stronger Brønsted acid sites. The catalytic activity for La–Ni–S2O82–/ZrO2–Al2O3-W was maintained at around 56% within 3000 min with an isopentane selectivity of 88% which showed much greater stability than that of La–Ni–S2O82–/ZrO2–Al2O3-I. This can be attributed to the fact that (1) the large pore size and pore volume of La–Ni–S2O82–/ZrO2–Al2O3-W can largely suppress carbon deposition and (2) the more numerous and stronger Brønsted acid sites for La–Ni–S2O82–/ZrO2–Al2O3-W guaranteed to provide enough acid sites for isomerization during the reaction process.

Toward Understanding of the Effect of Nucleation Temperature on Porous Structure of Micro-Mesoporous Composite Molecular Sieves and Related Crystallization Mechanism

Although micro-mesoporous composite molecular sieves have received significant attention due to their desirable properties, they still lack systematic studies on their crystallization process to achieve controllable synthesis of composite molecular sieves. In this study, a series of Y/SBA-15 micro-mesoporous composite molecular sieves with different porous structures were synthesized by tuning nucleation temperature, based on epitaxial growth on the outer surface of the Y-type crystal particle. All composite molecular sieves were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Moreover, the effect of nucleation temperature on the structure of composite molecular sieves was investigated, while the crystallization mechanism was also explored. Furthermore, the performance of the molecular sieves on isomerization of n-pentane was investigated, the results suggested that the isomerization selectivity was positively correlated with regularity degree of the mesoporous porous structure, where the highest isomerization reached 95.81%. This work suggests that nucleation temperature plays a key role in structures of micro-mesoporous composite molecular sieves, providing a solid basis for the further development of functional composite molecular sieves.

Effect of acidity and porosity changes of dealuminated mordenite on n-pentane, n-hexane and light naphtha isomerization

Abstract The purpose of this research work is to prepare and assess the catalytic performance of platinum (Pt) dealuminated mordenite for the of n-hexane, n-pentane and light naphtha isomerization. The Pt dealuminated mordenite was prepared by dealumination of commercial mordenite catalyst by refluxing using hydrochloric acid at 100 °C in various time durations (0.50, 1.0, and 3.0 h). The commercial as well as dealuminated mordenite catalysts were examined by X-ray diffraction analysis, X-ray fluorescence, N2 adsorption-desorption, Fourier-transform infrared spectroscopy, temperature-programmed desorption (NH3-TPD), scanning electron microscopy, and transmission electron microscopy with high resolutions XRD and BET surface area analysis. These afore mentioned studies confirm that the dealumination process exhibit an increasing the external surface area and improved the total acidity with retaining the structure of mordenite. The catalytic performance was investigated for the of n-hexane, n-pentane and light naphtha isomerization by varying factors such as, temperature, reaction pressure, hydrogen flow, hourly mass feed flow rate and catalyst mass. Among the catalysts, the dealuminated catalyst with SiO2/Al2O3 ratio of 40% exhibited highest conversion Pt–Cl–Al2O3 operate set the lowest temperature on and selectivity. The density functional theory (DFT) calculation implies that the activation free energy for isomerization of n-hexane varies with the position of interacting C–H bond with mordenite (Pt/Mordenite) cluster. Besides, the activation energy for the n-pentane isomerization is lesser than the n-hexane isomerization.

Isomerization of n-pentane catalyzed by amide-AlCl3-based ionic liquid analogs with various additives

Abstract The isomerization of n-pentane to generate high-quality blending components for clean gasoline was catalyzed by several amide-AlCl3-based ionic liquid (IL) analogs with various amides as donor molecules. The catalytic performance of these IL analogs was evaluated in a magnetic agitated autoclave operated in batch mode. IL analog based n-methylacetamide (NMA)-AlCl3 with the amide/AlCl3 molar ratio of 0.65 showed excellent performance toward n-pentane isomerization because 0.65NMA-1.0AlCl3 had a low viscosity and bidentate coordination structure. The influences of reaction time, reaction temperature, and stirring speed on the catalytic performance were also investigated. Optimal reaction conditions comprised the reaction time of 1 h, the reaction temperature of 40 °C, and the stirring speed of 1500 r·min−1. Under optimal condition, the n-C5 conversion, research octane number (RON) increment, total liquids yield, and isoparaffin yield in isomerized oil were 56.80%, 13.51, 89.90 wt%, and 44.32 wt%, respectively. A new mathematical model was constructed to predict the relationships among RON increment, RON increment/n-C5 conversion ratio, and n-C5 conversion. The new model indicated that an appropriate conversion per pass of n-C5 did not exceed 50%–55%. Various cycloparaffin additives were used to improve the catalytic performance of 0.65NMA-1.0AlCl3. The n-C5 conversion increased from 56.80% to 67.32%. The RON increment, total liquids yield, and isoparaffin yield reached 17.83, 97.36 wt%, and 63.74 wt%, respectively.

Effects of surface rates for the series reaction A → B → C on successive separated spherical sites

A steady - state series reaction A →B → C, consisting of a first reaction A →B on sphere 1 of radius a1 with first order kinetic rate constant kA and reactant diffusivity DA, followed by a second reaction B → C on sphere 2 of radius a2 with a first order kinetic rate constant kB and a B chemical species diffusivity DB, occurs on two discrete chemically active spheres a center - to – center distance d apart. The twin spherical harmonic expansion method with a Neumann iterative solution of the coefficient equations is used to generate a rigorous solution for the rate of series reaction in terms of an expansion in the inverse dimensionless center - to - center sphere separation d (=d⁄((a_1+a_2 ))) up to the inverse thirteenth power. The expansion coefficients depend on three dimensionless parameters (γ,λ_A,λ_B), where the dimensionless inverse surface kinetic constants are λ_A=D_A⁄a_1 kA on sphere 1, λ_B=D_B⁄(a_2 k_B ) on the sphere 2, while the geometry enters as the radius ratio γ=a_1⁄a_2 . Using these results an equivalent site kinetic change is imposed, first to λ_Aon site 1, then to λ_Bon site 2, to determine which site is more influential for the overall series reaction rate. Effects of γ geometry modification at several fixed kinetic surface site rates are examined. When either one of reactive spheres is diffusion controlled, various levels of λ kinetic controls at the other site or γ site geometries are generated to study the effects of site kinetics or geometry control on the series reaction rate. As the “other site” reaction rate also increases toward diffusion control, inflection points are observed to develop as precursors to a local maximum on the series reaction rate versus sphere separation curves. An application to the isomerization of n-pentane is presented.

Simulation of Hydroisomerization of n-Pentane into 2-Methylbutane on a Palladium-Containing Mordenite Catalyst

A stepwise mechanism for the isomerization of n-pentane into 2-methylbutane on a bifunctional palladium-containing mordenite catalyst is proposed and a corresponding kinetic model is built. Kinetic experiments are performed in a flow catalytic reactor. During the experiments, the reactor pressure varied from 10 to 30 atm, the reactor temperature varied from 603 to 640 K, and the hydrogen/n-pentane molar ratio varied from 2 to 10. The contact time (the ratio of the catalyst weight to the mass flow rate of the raw material) varied from 0.5 to 2 h. From the data of the kinetic experiment, the kinetic constants of the model and the constants of the distribution density of the observation errors are estimated by the maximum likelihood (ML) method. A sequential design of the kinetic experiment is implemented in order to precisely estimate the model constants and the kinetic model allowing us to predict the experimental results with an accuracy exceeding that of the starting experiments. The model is shown to be adequate for the experimental data obtained.

Isomerization of hydrocarbons over Pt supported on micro-mesoporous ZSM-5

Nanosized ZSM-5 with different Si/Al ratios, possessing both micro and mesopores, were synthesized by a hydrothermal method using tetrapropyl ammonium bromide (TPABr) as a template. The synthesised materials were characterized by different characterization methods to evaluate the phase purity, particle size, morphology, textural properties and acid strength. Pt (0.5 wt%) was loaded on the calcined (at 500 °C) ZSM-5 samples and evaluated for the isomerization of n-pentane, n-hexane and light naphtha. ZSM-5 as a catalyst showed higher conversions in comparison to other prepared zeolites with different SiO2/Al2O3 ratios. In addition, the ZSM-5(5.4) catalyst exhibited considerably higher conversions under most conditions. The reaction temperature, pressure, WHSV and H2 flow are key factors for this novel isomerization. The obtained results may have a great prospective in useful applications for humankind. In addition, the mechanism of the n-pentane, n-hexane and light naphtha isomerizations over the ZSM-5 zeolites was considered by density functional theory (DFT), using the cluster modeling approach.

Dicationic Ionic Liquid: A Novel Method for Improving the Isomerization Degree of n-Pentane

A series of dicationic ionic liquids were successfully prepared, and they were first used to convert the n-pentane into iso-alkanes as an environmentally safe way to improve the octane number of gasoline. As a novel and green catalyst, the dicationic ionic liquid [tetramethylethylenediamine(EtBr)2]-AlCl3 ([TMEDA(EtBr)2]-AlCl3) exhibits higher catalytic performance in n-pentane isomerization than the traditional monocationic ionic liquid [1-butyl-3-methylimidazolium]Cl-AlCl3 ([BMIM]Cl-AlCl3). And for the n-pentane isomerization reaction catalyzed by [TMEDA(EtBr)2]-AlCl3, the optimal reaction temperature, reaction time, and mass ratio of catalyst to oil were proven to be 100 °C, 3 h, and 1:1, respectively. For dicationic ionic liquid [TMEDA(EtBr)2]-AlCl3, the acid strength of it increases steadily with the increase of AlCl3 mole fractions. And the initiator is conducive to increasing n-pentane conversion, improving the yield of i-C5 and i-C6, and inhibiting the C4 component. Additionally, as the length of s...

Effects of zeolite particle size and internal grain boundaries on Pt/Beta catalyzed isomerization of n-pentane

The impact of particle size and internal grain boundaries of Beta zeolites was investigated in n-pentane isomerization over bifunctional Pt/Beta catalysts, by comparing the catalytic performance of four as-synthesized Pt/Beta samples that possess an identical Pt loading (0.5 wt%), but use four distinct Beta zeolites. Three of them contain polycrystalline zeolites, consisting of nano-sized crystals with a similar size of 9–13 nm, but having different average particle sizes (i.e., 1340, 830, and 250 nm) and numerous internal grain boundaries, as found via high-resolution transmission electron microscopy. The last catalyst contains single-crystalline zeolite, with an average particle size of 225 nm, and no observed internal grain boundaries. At low reaction temperature (<578 K), the particle size and internal grain boundaries do not change the apparent activity, because activity is controlled by reaction on the acid sites of the zeolite. At high reaction temperature (>614 K), a large particle size and the presence of internal grain boundaries significantly reduce the apparent activity, because of the extended diffusion path and additional diffusion barriers, which are probably caused by a mismatch in micropore alignment and gas-zeolite interfaces at these grain boundaries. Due to the small particle size and absence of internal grain boundaries, the observed activity for single-crystalline Beta can be 60–212% higher than for polycrystalline counterparts, even though it possesses a much weaker intrinsic acidity. This shows, remarkably, that single-crystalline zeolites with less internal grain boundaries can achieve a much higher catalytic activity.

A novel method for the synthesis of highly stable nickel-modified sulfated zirconia catalysts for n-pentane isomerization

A highly stable Ni modified sulfated zirconia catalyst was prepared by two different methods and used for n-pentane isomerization. The results showed that compared with the catalyst prepared by the sol-gel method, the catalyst prepared by the hydrothermal method showed higher surface area, larger pore size, smaller crystallite size of tetragonal ZrO2, more stable S-containing adsorbed species and a high isopentane yield. In particular, the Ni−/S2O82−-ZrO2–Al2O3, which was prepared by the hydrothermal method (Ni/SZA-R), provided a sustainable high isopentane yield (ca. 68%) with a slight deactivation (15%) only within 50h of continuous reaction. This result was ascribed to the catalyst's larger mean pore size and the increased concentration of more stable S-containing species formed compared to the catalyst prepared by the sol-gel method. The stability behavior of this Ni/SZA-R catalyst in terms of isopentane yield vs time appears by far larger (increase by a factor of ~ 2–15) compared to other non noble metal modified sulfated zirconia-based catalysts reported in the open literature.

N-pentane isomerization over Pt-Al promoted sulfated zirconia nanocatalyst

Platinum containing sulfated zirconia (Pt-SZ/Al) catalyst was prepared by precipitation method. Characterization of the prepared catalyst was performed using XRD and SEM, and catalytic activity was studied for isomerization of nC5 at atmospheric conditions and temperatures of 180-240C in a flow reactor. The eff ects of reaction temperature, H2/nC5 ratio, and WHSV were investigated. As revealed by SEM and XRD, the prepared sulfated zirconia was of nanoscale size and had predominantly tetragonal crystalline phase. n-pentane conversion increased with increasing temperature and selectivity decreased. The optimal reaction temperature was 220C where n-pentane conversion and isopentane selectivity were 70% and 94%, respectively. The positive e ffect of H2/nC5 ratio was observed on nC5 conversion and iC5 selectivity in the investigated H2/nC5 ratio range. This trend of variation was related to the role of acid and metallic siteson the reaction pathway. As expected, increase in the WHSV, which reduces contact time between reactant and catalyst, decreased nC5 conversion and increased selectivity toward iC5. The RON of the product increased with increasing temperature; then, it showed slight decrease at higher temperature. The decrease in the activation energy was observed, which can be attributed to the di erent reaction mechanisms or di fferent rate-determining steps.

Skeletal isomerization of n-pentane: A comparative study on catalytic properties of Pt/WOx–ZrO2 and Pt/ZSM-22

Pt/WOx–ZrO2 and Pt/ZSM-22 were prepared and used as catalysts for the n-pentane hydroisomerization reactions. The physico-chemical properties of the supports were characterized by XRD, N2 adsorption, NH3-TPD and 1-pentene isomerization reaction. The reducibility and adsorbability of the catalysts were evaluated via H2-TPR, H2-TPD and CO adsorption. Under the reaction condition of WHSV=1h−1, pn-pentane,0=0.24bar and ambient pressure, the yields of isopentane over Pt/WOx−ZrO2 and Pt/ZSM-22 can reach 52% (at 300°C) and 61% (at 340°C) respectively. The selectivities to isopentane over these two catalysts are well above 95%. The hydroisomerization mechanisms over these catalysts are discussed.

Effect of Preparation Conditions on the n-Pentane Isomerisation Performance of Pt-S2O82–/ZrO2–Al2O3 Catalysts Prepared by the Microemulsion Method

Pt-promoted S2O82–/ZrO2–Al2O3 (SZA) catalysts were successfully prepared by the microemulsion (Pt-SZA-M) and impregnation (Pt-SZA-I) methods. The effects of the preparation parameters (surfactant-to-oil ratio, surfactant-to-cosurfactant ratio, types of cosurfactant and oil phase, etc.) on the catalytic activity of Pt-SZA-M catalysts in the isomerisation of n-pentane were investigated. The results showed that the optimal catalyst preparation conditions were: a cetyltrimethylammonium bromide (CTAB)/ n-butanol mass ratio of 4:6, a (CTAB + n-butanol)/cyclohexane mass ratio of 3:7, a content of H2PtCl6 solution in microemulsion of 3.6 wt% and a N2H5OH/H2PtCl6 molar ratio of 25:1. A comparison of the isopentane yield for Pt-SZA-M with that for Pt-SZA-I was also performed. The results showed that the microemulsion method led to smaller and more uniform Pt particles (4.5 nm) on the SZA. In comparison with Pt-SZA-I, the isopentane yield for Pt-SZA-M was increased by 13.5% at 180 °C, showing the catalytic performance of Pt-SZA-M at lower temperature was improved significantly. At a reaction temperature of 230 °C, a pressure of 2.0 MPa, a hydrogen/ n-pentane molar ratio of 4:1 and a weight hourly space velocity of 1.0 h−1, the yield of isopentane for Pt-SZA-M reached 60.8%.