Surface Acid Strength Research Articles

Organic Acid‐Assisted Preparation of Hydroxyapatite‐supported Ni Catalysts for Arene Hydrogenation

Developing non‐noble metal catalysts that can efficiently and selectively hydrogenate arenes remains a significant challenge. In this study, we developed efficient Ni catalysts for the arene hydrogenation based on an organic acid‐regulated impregnation strategy. These easily accessible Ni catalysts demonstrated exceptional efficiency, selectivity, reusability, and good substrate compatibility. The influence of carbon chain lengths and side‐chain hydroxyl or amino groups on dicarboxylic acids used in the catalyst preparation was comprehensively investigated. Characterizations and kinetic studies demonstrated the influence of organic acids on the size of Ni nanoparticles, the proportion of metallic nickel, and the strength of surface acidity. These factors influenced the activation of arene and hydrogen, thereby affecting the hydrogenative activity. Notably, hydroxyapatite‐supported Ni catalyst, assisted by tartaric acid (Ni‐TA/HAP) with an appropriate tartaric acid‐to‐nickel ratio, resulted in relatively smaller Ni nanoparticles, an increased proportion of Ni0, and more acidic sites, thereby exhibiting the best hydrogenation performance.

CO2 hydrogenation to light olefins using In2O3 and SSZ-13 catalyst − Understanding the role of zeolite acidity in olefin production

With the aim to explore the effect of acidic properties of zeolites in tandem catalysts on their performance for CO2 hydrogenation, two types of SSZ-13 zeolites with similar bulk composition, but different arrangements of framework Al, were prepared. Their morphology, pore structure, distribution of framework Al, surface acid strength and density, were explored. The results showed that SSZ-13 zeolites with isolated aluminum distribution could be successfully synthesized, however, they contained structural defects. During calcination, the framework underwent dealumination, resulting in weaker Brønsted acidity and lower crystallinity. The morphologies were, however, well preserved. Compared with the SSZ-13 zeolites, synthesized conventionally, these low acidity SSZ-13 zeolites with isolated aluminum were good zeolite components in bifunctional catalysts for CO2 hydrogenation to light olefins. By combining with In2O3, they exhibited better catalytic performance for light olefin production during CO2 hydrogenation at low temperatures. Na+ cation exchange was used to adjust the Brønsted acid site (BAS) density with only minor changes to the cavity structure. Comparative experiments established that the BAS density of the zeolite, rather than the framework Al distribution (BAS distribution), overwhelmingly affected catalyst stability and product selectivity. A higher acid density reduced the selectivity for light olefins, while lower acid density tended to form inert coke species leading to rapid deactivation. The ideal amount of BAS density in the bifunctional catalyst was approximately 0.25 mmol/g, which exhibited 70% selectivity for light olefins among hydrocarbons, and 74% selectivity for CO without deactivation, after 12 h reaction at 325 ℃ and 10 bar.

MnCe/GAC-CNTs catalyst with high activity, SO2 and H2O tolerance for low-temperature NH3-SCR

SO2 and H2O tolerance is a crucial issue for low-temperature selective catalytic reduction of NO with NH3 (NH3-SCR) in practical application. In the present work, MnCe/GAC-CNTs catalysts were prepared and showed high activity, SO2 and H2O tolerance for low-temperature NH3-SCR. The catalysts were characterized by SBET, XPS, XRD, NH3−TPD, and DRIFTs. MnCe/GAC-CNTs exhibited higher catalytic activity and H2O + SO2 tolerance than CeO2/GAC-CNTs due to electron transfer between Ce and Mn species (Ce4+ + Mn3+ ↔ Ce3+ + Mn4+) accompanied with higher proportion Ce3+, and the improvement of surface acidity concentration and strength. Besides, Mn addition inhibited the oxygen inhibitory effect, enhanced the adsorption of NO, and increased the proportion diameter, which were beneficial to SO2/H2O resistance. Furthermore, the presence of Mn suppressed the formation of hydroxyl group, inhibited the adsorption of SO2, ultimately limited electron transfer between SO2 and Ce4+, which led to high SO2 tolerance of the MnCe/GAC–CNTs catalyst. Therefore, MnCe/GAC-CNTs catalyst with high deNOx performance and SO2/H2O tolerance, showed the potential of practical low-temperature deNOx application.

Specific chemical adsorption of selected divalent heavy metal ions onto hydrous γ-Fe2O3-biochar from dilute aqueous solutions with pH as a master variable

A γ-Fe2O3-biochar was synthesized using ferrate as precursor. Results showed that ferrate treatment of biochar increased surface acidity and magnetism strength, which enhanced metal ion adsorption and enabled easy magnetic separation of spent biochar after use. The adsorption characteristics of selected metal ions including Cu(II), Pb(II), Zn(II), Ni(II), Cd(II) and Co(II) onto hydrous γ-Fe2O3-biochar were studied. The adsorption isotherms were well fitted by the Langmuir adsorption model. The γ-Fe2O3-biochar exhibited significantly high monolayer metal coverage capacity. For example, the maximum Cu(II) adsorption density was 55.45 × 10-5 mol/g, which was 4.0 times that of plain biochar (13.75 × 10-5 mol/g) at pH 6. Metal ion adsorption reactions could be described by surface complex formation, involving all M(II) hydroxy species and surface hydroxy species, i.e., ≡FeOH and ≡COH. Both experimental and calculation results suggested the formation of inner- and outer-sphere complexes. Coulombic and specific chemical forces contributed to the total adsorption energy, with specific chemical energy being the dominating component for the adsorption of hydrolyzable metal ions onto γ-Fe2O3-biochar surface. Under the context of surface complex formation, it is visualized that metal ion hydrolysis reactions occurred on γ-Fe2O3-biochar surface, in parallel to that in the bulk phase.

Optimizing acido-basic profile of support in Ni supported La2O3+Al2O3 catalyst for dry reforming of methane

The increasing alarm of global warming always draws interest in reactions like dry reforming of methane (DRM) where both global warming gases (CO2 and CH4) are converted into value-added chemical building blocks, such as syngas. Nickel catalyst active sites along with support acid-base profiles play a key role in DRM. Herein, xLa2O3+(100-x) Al2O3 (x = 0, 10, 15, 20%) supports are prepared and followed by NiO dispersion over the produced support by impregnation method. It was tested for DRM reaction and characterized with TGA, XRD, TEM, IR, Surface area and porosity measurement, H2-TPR, CO2-TPD and NH3-TPD techniques. Upon increasing the basic lanthana proportion in the acidic alumina support, the crystallinity of alumina and acidity of total support decline. Up to 15% Lanthana addition in support claims a low acid and rich basic surface including super basic sites (related to unidentate carbonates) which governed optimum catalytic performance 64% CH4 conversion, 79% CO2 conversion and H2/CO ~ 1 up to 460-min in time on stream test. 20% lanthanum oxide loading led to inferior performance due to rapid loss of surface area, pore-volume, pore diameter, acidity and medium basic strength sites. Fine-tuning of acid-base lanthana-alumina support with dispersed Ni species are a means for understanding DRM.

MCM-41 grafted with citric acid: The role of carboxylic groups in enhancing the synthesis of xanthenes and removal of heavy metal ions

Order mesoporous MCM-41 was synthesized via a sol-gel method and then grafted by adding the appropriate amount of citric acid (CA). The structure and morphology of pure and grafted mesoporous MCM-41 were investigated by XRD, BET, TEM, and FT-IR measurements. TEM measurements confirm that MCM-41 particles display an ordered structure with uniform mesoporous arranges into a hexagonal, honeycomb-like lattice and still preserved their mesoporous structure after grafting with different weight contents of CA. The pore sizes and volume of the CA/MCM-41 samples were found to vary markedly within CA contents. The surface acidity and the type of acid sites (Brønsted and Lewis) were determined using the potentiometric titration method and the FTIR of pyridine adsorption. In this work, it was found that the textural, acidic properties and the activities of catalysts could be improved by citric acid treatment The results illustrated that the surface acidity and acidic strength of CA/MCM-41 gradually increased with increasing the CA amount up to 50 wt.%. Also, the prepared catalysts showed both Brönsted and Lewis acid sites and the number of Brönsted acid sites increased largely compared with Lewis acid sites with increasing the CA content which indicates the role of carboxylic groups in enhancing the Brönsted acid sites. The catalytic performance of the samples was tested by the synthesis of 14-Phenyl-14H-dibenzo [a, j] xanthene (xanthene). In this reaction, the sample with 50 wt.% of CA displayed the highest acidity and catalytic activity. The adsorption activity was examined for removing Cd2+ and Pb2+ from aqueous solution with varying parameters such as pH, concentration, temperature and time. The equilibrium adsorption data obtained fitted with the Langmuir model and the adsorption kinetics favored the pseudo 2nd order model. Also, the adsorption was spontaneous and exothermic.

Regeneration of alkali poisoned TiO2-based catalyst by various acids in NO selective catalytic reduction with NH3

The K2O poisoned CuNbTi as a model catalyst (K-CuNbTi) was regenerated by various type and strength acids, among which H2SO4, C2H2O4 and H6O39SiW12 exhibited higher regeneration efficiencies. In contrast to H2O treatment, most potassium depositing on the surface of K-CuNbTi could be removed successfully for the acids regenerated catalysts. All the regenerated catalysts showed above 90% NOx conversion and 98% N2 selectivity in the temperature range of 300–350 °C under a high GHSV of 177,000 h−1. And the regenerated catalysts were characterized by different analytic techniques. Both of the surface chemical active oxygen species and the Cu+ species were obviously improved while KNbO3 was transformed into Nb = O and Nb–OH after regeneration process. Furthermore, the quantity and strength of surface acidity were enhanced and more acid sites were generated, especially Brønsted acid sites. The main acid sites of K-CuNbTi was Lewis acid sites while Brønsted acid sites became the dominating acid sites for the regenerated K-CuNbTi catalysts. Also, acid regeneration process promoted –NH2 active species formation on the catalyst. All above induced a better catalytic activity of regenerated catalyst, indicating that oxalic acid and silicotungstic acid could be the potential substitutes for sulfuric acid to regenerate alkali poisoning SCR catalysts.

Preferred enhancement of fast-SCR by Mn/CeSiOx catalyst: Study on Ce/Si promotion and shape dependence

A series of Mn/CeSiOx catalysts were synthesized to investigate the Ce/Si ratios and morphology effect of Ce/SiOx support for the selective catalytic reduction (SCR) of NO with NH3 at low temperature. The characterization and catalytic test showed that the 0.3Mn/Ce8Si2Ox-R catalyst exhibits high NOx conversion at low temperature. The Ce/Si ratio was 8/2 over the 0.3Mn/Ce8Si2Ox-R catalyst, increasing the surface acidity and inhibiting the side reaction of NH3. The {110} and {100} facts of the nanorod structure are rich in Ce3+ species and oxygen vacancies for the SCR reaction. Moreover, the citric acid method was employed on 0.3Mn/Ce8Si2Ox-R-CA to improve the interaction between Mnn+ and Ce8Si2Ox-R and enhance the strength of surface acidity, leading to the highest NOx conversion and Fast-SCR process. During the suppression effect of SO2 or HCl on catalytic activity, the 0.3Mn/Ce8Si2Ox-R-CA catalyst shows higher poison resistance to HCl than SO2.

Green synthesis of ester base oil with high viscosity – Part Ⅰ: Catalyst preparation, characterization, evaluation, and mechanism analysis

High viscosity ester base oil, as an eco-friendly lubricant base oil with high performance, can significantly reduce the friction, wear, and energy consumption of large machinery. However, there is less research on the preparation of heterogeneous catalysts for synthesis of high viscosity ester oil. In this work, Sn/Zr mixed oxide catalysts were prepared for the green synthesis of ester base oil with high viscosity. This approach gets rid of additional template, surfactant, organic solvent, sulfur, nitrogen, phosphorus, and halogen, thereby avoiding the potential environmental pollution. A superior powdered catalyst MO-Sn8Zr-9.0-160-18 was developed with optimized Sn/Zr molar ratio, pH, hydrothermal temperature, and hydrothermal time of 8:1, 9.0, 160 °C, and 18 h, respectively. Results of catalyst characterization indicated that the developed catalysts were mesoporous materials with hydrophobic properties, allowing for free diffusion of macromolecules, adsorption of reactants, and desorption of water. Additionally, the specific surface area, pore volume, pore diameter, and surface hydrophobicity of catalyst were enhanced by doping Zr, so the catalysts with higher [Sn/Zr]ICP/[Sn/Zr]XPS exhibited better catalytic activity. Preformed catalyst was prepared by simple mechanical mixing method to achieve better catalyst separation. The specific surface area, acid amount, and acid strength of catalyst were indeed improved significantly after catalyst molding. By programmed heating, the preformed catalyst achieved a maximum carboxyl conversion of 97.2%. Moreover, spent catalyst could be reactivated via solvent washing, drying, calcination, and hydrogen reduction, exhibiting good reusability.

Influence of preparation methods on iron-tungsten composite catalyst for NH3-SCR of NO: The active sites and reaction mechanism

A series of iron-tungsten composite oxides catalysts prepared by grinding methods (FW-GR), incipient impregnation (FW-IM), sol–gel (FW-SG) and microemulsion (FW-ME) methods were used for selective catalytic reduction of NO by NH3 (NH3-SCR). The SCR activity was significantly depended on the preparation method, the NO conversions over different catalysts were following the order of FW-GR > FW-SG > FW-ME > FW-IM. The results indicated that the NO conversion was strongly related to the FeWO4 species. It also discovered that the catalyst with higher specific surface area, surface Fe2+ content, surface adsorbed oxygen species, redox potential, surface acidic sites and acidic strength showed better NO reduction activity among all catalysts. In situ DRIFTS results revealed that the main reaction mechanisms of iron-tungsten catalysts were “L-H” at low temperature and “E-R” at high temperature. The SCR reaction over FW-GR sample involved the formation of NH2 intermediate and subsequent reduction by NO, while the formation of NH4NO3 species over FW-IM was easily transformed into N2O species.

Hydrocracking and hydrodesulfurization of diesel over zeolite beta-containing NiMo supported on activated red mud

NiMo nanocatalysts supported on activated red mud with different zeolite beta contents were successfully prepared by impregnation technique. Their hydrocracking and hydrodesulfurization activities were evaluated with two different kinds of diesel feed (iso diesel and heavy diesel) in a fixed bed reactor at ambient pressure and 500 °C. Physico-chemical properties of synthesized samples were characterized using the methods of XRF, XRD, FESEM, BET, FTIR and NH3-TPD. The results indicated that zeolite incorporation resulted in a significant increase in specific surface area (BET result) and acidic strength (TPD result) of nanocatalysts. FESEM analysis confirmed that the particles size of zeolite-containing NiMo/ARM was less than 100 nm and the average size of particles was about 30 nm. Hydrocracking results illustrated that incorporation of zeolite beta improved cracking activity considerably. In addition, NiMo nanocatalyst containing 37.5 wt% of zeolite had the highest yields of desirable products (naphtha, kerosene and diesel) and the highest conversion. Moreover, the flash point and viscosity of the liquid product decreased notably the nanocatalysts with 37.5 wt% and 12.5 wt% of zeolite were able to remove approximately 96% and 72% of the sulfur content of iso diesel and heavy diesel, respectively.

Trade-Off between Acidic Sites and Crystallinity of the WO3–TiO2 Catalyst toward Dehydration of Glucose to 5-Hydroxymethylfurfural

The dehydration of glucose to 5-hydroxymethylfurfural (HMF) is one of the most coveted catalytic reactions from energy and environmental perspective. In spite of the exhaustive work, the understanding of the reaction mechanism is still debated in literatures. Here, the composite WO3–TiO2 catalyst was synthesized by different routes such as solution combustion synthesis method and microwave-assisted hydrothermal method for the glucose dehydration reaction. The synthesized materials were structurally characterized by X-ray diffraction, Raman spectroscopy, and UV–vis diffuse reflectance spectroscopy. The surface morphology was studied with field emission scanning electron microscope and surface area analysis. The surface acidity and total acidic site strength of the synthesized materials were revealed by pyridine Fourier transform infrared spectra and temperature-programmed desorption of ammonia. The results showed that the solution combustion-synthesized materials upon calcination become more crystalline, h...

Role of alkali sodium on the catalytic performance of red mud during coal pyrolysis

Red mud (RM) as large quantity of industrial wastes could serve as a low-cost catalyst for catalytic upgrading of coal pyrolysis volatiles. However, the catalytic performance of raw RM for improving the quality of tar was limited because of its composition and structure. In this paper, the RM-based catalyst (RMC) for coal pyrolysis was prepared by using acid-alkali treatment. It was found that changing sodium content could modify the characteristics of RMC. The BET and NH3-TPD showed that the surface area and acid strength of RMC increased evidently with the reduction of sodium content. The pyrolysis characteristics of samples by mix shaping of coal and RMC with different sodium contents were evaluated in a fixed-bed reactor. The addition of RMC into coal could upgrade tar quality, thus increasing the yield of light tar (boiling point <360 °C) and decreasing the yield of heavy tar. The content of sodium in the RMC had a great influence on product distribution of coal catalytic pyrolysis. The low-content sodium with high concentration acids contributed to the formation of coke. Whereas, with the increase of sodium content in RMC, coking was suppressed but more gaseous products were produced. After adding 4 wt% RMC with sodium content of 3.2 wt% into coal, the yield of light tar increased to 7.7 wt% and the light fraction in tar was as high as 74%, much higher than those from coal pyrolysis without catalyst.

Selective hydrogenolysis of glycerol to 1,3-propanediol over Pt-WOx/SAPO-34 catalysts

Selective catalytic hydrogenolysis of glycerol to 1,3-PDO is cost-effective for both production of the 1,3-PDO with an increasing industrial demand and valorization of the glycerol derived from biodiesel production, and both acid and metal are thought necessary for the catalysts for the reaction that proceeds by a dehydration-hydrogenation mode. Acidic mesoporous SAPO-34 was synthesized by a hydrothermal method and used to load Pt and WOx. The prepared Pt/SAPO-34 catalyst was active for glycerol hydrogenolysis due to its surface acidity and textural properties except for a low selectivity to 1,3-PDO. The WOx introduced on Pt/SAPO-34 markedly promoted glycerol conversion and the selectivity to 1,3-PDO. The content of WOx was found vital for the reaction, and the optimized catalytic performances were realized on the Pt-WOx/SAPO-34 catalyst with 20% WOx. The optimized content of WOx in the Pt-WOx/SAPO-34 catalyst was confirmed as non-stoichiometric and highly dispersed polymerized tungsten oxide species, and strongly interacted with the metallic platinum loaded. Accordingly, the metallic platinum was well dispersed on the WOx/SAPO-34. Moreover, the decoration of WOx enhanced the strength of surface acidity of the Pt/SAPO-34 catalysts in term of weak and moderate acid. Moreover, long reaction time, low reaction temperature and high reaction pressure facilitated the selective production of the desired 1,3-PDO from glycerol.

Role of cerium in improving NO reduction with NH3 over Mn–Ce/ASC catalyst in low-temperature flue gas

Mn–Ce mixed oxide was loaded onto activated semi-coke (ASC) via impregnation method and the low temperature selective catalytic reduction (SCR) of NO with NH3 was investigated. The NO conversion and NO oxidation rates were both influenced by the ratios of Ce/(Mn+Ce), and Mn–Ce(0.3)/ASC with loading 5% (mass ratio) Mn–Ce oxides performed the highest catalytic conversion rate of 96.6% and NO oxidation rate of 18.4% at 250°C and GHSV=6000h−1. The changes of physical properties, microstructure, functional groups, crystal structure, surface atomic state, redox property and acid strength for the catalysts were characterized by BET, SEM, FT-IR, XRD, XPS, H2-TPR and NH3-TPD. The results showed that surface functional groups were increased after nitric acid treatment and abundant oxygen groups were observed on semi-coke surface, which were considered to be beneficial for the gas adsorption. Ce doping could raise the Mn4+/Mnx+ rate which played a vital role in catalytic reaction, enhancing the amount of weak and strong acid sites, increasing oxygen vacancies and accelerating the molecular oxygen turning into reactive oxygen species, which could enhance the NO oxidation activity thus contributed to the denitration efficiency.

Input of different kinds of soluble pectin to cation binding properties of roots cell walls

It is widely believed that pectin are responsible for the vast majority of cation binding positions in the root cell walls. To estimate the role of particular kinds of pectin, we studied the cell wall material isolated from the roots of monocots (wheat and rye) and dicots (clover and lupine) before and after removal of different fractions of soluble pectin. Simultaneously PME activity and degree of pectin methylation were determined. From potentiometric titration curves cation exchange capacity, total surface charge and acidic strength of surface functional groups responsible for surface charging were determined. Monocots had smaller cation exchange capacity and lower pectin content than dicots. Removal of pectin induced up to 50% reduction in the cell walls surface charge. Pectin seem to have more acidic character than the other roots components that is seen from an increase in very weakly acidic groups fraction and significant decrease in the average dissociation constant of the cell walls material after pectin removal. Water soluble pectin and non-pectic soluble compounds had the dominant role in surface charging, while chelator and diluted alkali soluble pectin contributed to surface charge only at high pH's.

Zr-modified hierarchical mordenite as heterogeneous catalyst for glycerol esterification

Hierarchical mordenite catalysts were prepared by HF and NH4F etching. Materials' zirconia modification was performed by incipient wetness impregnation in order to vary surface acidity type and strength. XRD, N2 physisorption, solid-state NMR and UV–Vis spectroscopies were applied for characterization. Acidic properties of the obtained materials were investigated by TPD of adsorbed ammonia and FT-IR spectra of adsorbed pyridine. Catalytic performance was studied for the glycerol esterification with acetic acid. Zr increased reaction turnover activity compared to raw zeolite substrate due to abundant Brönsted and Lewis moiety presence. The demonstrated biomass valorization processes to bio-based platform chemicals are of interest, as they employ biodiesel production waste.

DME synthesis from methanol over hydrated γ-Al2O3(110) surface in slurry bed using continuum and atomistic models

The possible paths of dimethyl ether (DME) synthesis from methanol over hydrated [Formula: see text]-Al2O3(110) in vacuum and liquid paraffin have been investigated by using density functional theory (DFT). Over hydrated [Formula: see text]-Al2O3(110), the three possible paths of methanol dehydration to DME have been investigated by the DFT method in vacuum and liquid paraffin. DME synthesis from methanol is carried out along the same pathway 2CH3OH(g) [Formula: see text] 2* [Formula: see text] 2CH3OH* [Formula: see text] 2CH3O* [Formula: see text] 2H* [Formula: see text] CH3OCH3* [Formula: see text] H2O* in vacuum and liquid paraffin, and the step of highest energy barrier is the reaction of 2CH3O* [Formula: see text] CH3OCH3* [Formula: see text] O*. The energy barrier of the step in liquid paraffin is higher than that in vacuum by 0.33[Formula: see text]eV. The surface acid strength in liquid paraffin decreases over [Formula: see text]-Al2O3(110) surface comparing with vacuum, showing that stronger surface acid strength benefits to DME synthesis. Our result is in consistent with the experiment results.

Efficient production of 5-ethoxymethylfurfural from fructose by sulfonic mesostructured silica using DMSO as co-solvent

The use of sulfonic acid-functionalized heterogeneous catalysts in conjunction with the use of dimethyl sulfoxide (DMSO) as co-solvent in the catalytic transformation of fructose in ethanol to produce 5-ethoxymethyl furfural (EMF) is shown as an interesting alternative route for the production of this advanced biofuel. Arenesulfonic acid-modified SBA-15 mesostructured silica (Ar-SO3H-SBA-15) has been the most active catalyst, ascribing its higher catalytic performance to the combination of excellent textural properties, acid sites surface concentration and acid strength. Noticeably, DMSO promotes the formation of EMF and HMF, reducing the extent of side reactions. Reaction conditions (temperature, catalyst loading and DMSO concentration) where optimized for Ar-SO3H-SBA-15 via response surface methodology leading to a maximum EMF yield of 63.4% at 116 °C, 13.5mol% catalyst loading based on starting fructose and 8.3vol.% of DMSO in ethanol after 4h of reaction. Catalyst was reused up to 4 consecutive times, without regeneration treatment, showing a slight gradual decay in activity attributed to the formation of organic deposits on the catalyst’s surface.

An improvement of MCM-41 supported phosphoric acid catalyst for alkylation desulfurization of fluid catalytic cracking gasoline

The theoretical calculation about the catalytic mechanism of MCM-41 supported phosphoric acid (SPAM) in the alkylation desulfurization of fluid catalytic cracking (FCC) gasoline demonstrated that properly reducing the amount of effective acid on the surface was beneficial to further enhancing the catalyst performance. Based on the previously optimized preparation of SPAM (weight ratio of total acid/MCM-41 6:1, calcination temperature 773K and weigh ratio of H3PO4/H4P2O7 1:2.5), an improvement by diluting the concentration of mixed phosphoric acids in the impregnating solution was carried out in this work. The surface structure and catalytic behavior of improved SPAM were investigated by structural characterization and experimental verification, respectively. The results proved that decreasing the concentration of mixed phosphoric acids in the impregnating solution in the preparation of SPAM could effectively reduce the existing acid amount on the catalyst surface by increasing the catalyst crystallinity, and both the surface acid strength and the total acids amount of SPAM were reduced. Moreover, the catalytic activity and selectivity of improved SPAM for thiophenic sulfurs alkylation in the alkylation desulfurization were enhanced and the olefins polymerization reactions were suppressed to a lower extent. Besides, the theoretical calculation was verified by this study, which opened a particularly appealing opportunity for the application of SPAM in the industrial alkylation desulfurization of gasoline.