Strong Acid Sites Research Articles

Directed thermocatalytic CO2 reduction over NiAl4 layered double hydroxide precursors − activity and selectivity control using different interlayer anions

The use of rare nickel-poor and aluminum-rich layered double hydroxides (LDHs) as catalyst precursors in CO2 hydrogenations has revealed the key importance of chemical quality of the interlayer anions for the achievable CO2 conversion and CH4/CO selectivity. At atmospheric pressures between 300 and 700 °C, the obtained CH4 and CO formation rates varied widely, reaching up to the remarkable 76.8 (LDH-NO3) and 47.7 μmol/gcats (LDH-NH2SO3), respectively, competing with Pt and Co containing catalysts. Depending on thermal stability of the interlayer anions, their partial or complete removal resulted in significant differences in LDH transformation and thus in reducibility of Ni(II) and specific surface area values of the resulting metal oxides. Moreover, clear correlation was found between the conversion, selectivity and the abundance, strength of base and acid sites presented in the calcined LDHs related to the nature of starting interlamellar anions. Incorporation of nitrate and perchlorate ions into the precursors helped the formation of weak basic sites, while sulphate and sulphamate ions resulted in a large number of strong acid and base sites. The high-resolution quasi in situ X-ray photoelectron spectra revealed the effect of the anions on chemical composition of the forming catalytic interfaces. Meantime, the in situ diffuse reflectance infrared spectroscopy measurements indicated multifarious CO2 hydrogenation pathways via formate (LDH-NO3, -Br, -I), carboxylate (LDH-Cl, -ClO4) intermediates and CO2 dissociation (LDH-SO4, -NH2SO3).

Assembly of hydrolysis, activation and reforming sites boosting steam reforming of DME over ZnO/TiO2 catalysts

Steam reforming of dimethyl ether (DME SR) through the tandem reactions of DME hydrolysis to methanol and methanol steam reforming (MSR) is a promising process for feeding hydrogen to fuel cells. Herein, we synthesize a series of ZnO/TiO2 catalysts with different Zn contents for DME SR. We discover that TiO2 exhibits excellent methanol activation ability by forming a large amount of methoxy species, and adjacent ZnO sites can directly utilize them for the substantial steam reforming. Compared with TiO2 and ZnO alone, the MSR reaction rate over the 2ZnO/TiO2 catalyst (with a Zn content of 2 wt%) at 340 °C increases by 56 and 38 times, respectively. For DME SR, DME hydrolysis could occur on strong acidic sites of the TiO2 support to generate methanol molecules to subsequently involve in MSR. The synergy as described above significantly enhances the DME SR activity. Additionally, the adsorption strength of the oxygenated intermediates formed on the ZnO/TiO2 catalysts is weaker than that on TiO2, which then inhibits the reactions of methanation and methanol/DME decomposition. The 2ZnO/TiO2 catalyst exhibits low CO (2.8%) and CH4 (0.3%) selectivity with DME conversion of 92% in DME SR at 400 °C.

Effects of parameters in the preparation of Mo/MWW-type catalysts on the dehydroaromatization of shale gas

The direct non-oxidative aromatization of shale gas offers an unconventional production route for BTX (benzene, toluene, and xylene), potentially alleviating the heavy dependence of BTX supply on petroleum-based processes. Zeolite-supported transition metal catalysts have been successfully applied in the aromatization of light alkanes, where the zeolites provide the appropriate shape selectivity and acidity that are beneficial for the production of aromatics. In addition to HZSM-5, MCM-22 has also been recognized to be an effective support, owing to the characteristic topology of MWW structure. Here, we present a systematic investigation into the preparation and optimization of Mo/MWW-type catalysts, aiming to maximize their performance in shale gas aromatization. Mo/MCM-22 exhibited a superior initial BTX yield compared to Mo/ZSM-5 with a comparable Si/Al ratio, but was rapidly deactivated. A moderate value of Si/Al (∼ 11) was required for optimal catalytic performance, as an excessive amount of Al during the synthesis of MCM-22 led to insufficient amount of strong acid sites that are favorable for the reaction. The inclusion of Ga in MCM-22 greatly deteriorated the aromatization activity, owing to a significant degree of degalliation under reaction conditions. Contrary to ZSM-5, pelletization of MCM-22 also had a noticeable impact on catalytic performance, which was attributed to the nature of MWW topology. These results provide a comprehensive understanding of designing MWW-type zeolites for their application in shale gas aromatization.

Numerical and statistical determinations of the controlling factors in biomass-derived alcohol dehydration over La-incorporated γ-Al2O3 catalysts

This study aimed to develop a sustainable and renewable production process for linear α-olefins (LAOs) through the dehydration of alcohols. Lanthanum (La)-incorporated γ-Alumina (Al2O3) was selected as the catalyst, with a loading of up to 10 wt%. The addition of La modified the properties of Al2O3, including its acidity and basicity. The prepared catalysts were then used to dehydrate 1-octanol, resulting in the selective production of 1-octene due to the suppression of isomerization activity by lanthanum oxide (La2O3) species anchored on Al2O3, which caused a significant decrease in the number of strong acid sites of Al2O3. The effects of temperature and La loading on the dehydration and isomerization rates were also investigated. The results revealed that the reaction temperature had a stronger influence on the isomerization rate, while the La loading had a greater impact on the dehydration rate. The addition of 5% La to Al2O3 enabled the selective formation of 1-octene with high yield (90.9%), purity (92.3%), productivity (69.9 mmol1-octene gcat–1h−1), and moderate separation energy (317 kJ mol–1h−1) to achieve 99% 1-octene purity. At a comparable 1-octene productivity of 66–67 mmol1-octene gcat–1h−1, the addition of 5 wt% La resulted in a lower separation energy (290.3 kJ mol–1h−1) than that of Al2O3 (349.4 kJ mol–1h−1). This finding is particularly beneficial in the production of poly α-olefins that requires high purity LAOs.

CO2 conversion into hydrocarbons via modified Fischer-Tropsch synthesis by using bulk iron catalysts combined with zeolites

To effectively address the challenges posed by global warming, a prompt and coordinated effort is necessary to conduct an extensive study aimed at reducing CO2 emissions and overcoming the obstacles presented by expensive and scarce fossil fuel resources. This study primarily focuses on comparing two different methodologies for preparing Na-promoted Fe3O4-based catalysts for the CO2 hydrogenation into hydrocarbon mixtures. Three catalysts were synthesized and tested: two samples were impregnated with a different amount of Na (1 wt% and 5 wt%), while a third one was obtained via coprecipitation with NaOH. As the latter catalyst exhibited the best performance, it was combined with zeolites in two ways: physical mixtures and core-shell structures. MFI-type zeolites were used in both configurations and a conventional structure was compared to a hierarchical one. As a result, mesopores increased successfully both the CO2 conversion from 37% to 40% and the liquid hydrocarbon (C6+) selectivity from 29% to 57%, doubling the C6+ yield. On the other hand, NH3-TPD and XPS measurements demonstrated that the intimate contact between the two materials in the core-shell structures led to the migration of Na from the oxide to the zeolite reducing the concentration of strong acid sites and, consequently, the liquid hydrocarbon yield.

Temperature-dependent synthesis of dimethyl ether (DME) from methanol over beta zeolite: a novel approach to a sustainable fuel.

Crystalline beta zeolite molecular sieve with SiO2/Al2O3 molar ratio of 28.5 was synthesized by the hydrothermal crystallization method and examined for methanol dehydration reaction. The micro-mesoporous beta zeolite was active between 280 and 450°C. Dimethyl ether (DME) was observed as the predominant product at all reaction temperatures, with a maximum selectivity of 47.9% at 300°C and a methanol turnover frequency (TOFMeOH) of 741.9 h-1. At increased reaction temperatures, beta zeolite showed enhanced strong acid site fraction, promoting higher hydrocarbon formation following the olefin-based cycle. It was revealed that the crystallinity, porosity and acidity of beta zeolite change in the reaction environment. Amorphous carbon deposition occurred on beta zeolite, which involved a loss in crystallinity to some extent. The temperature increase showed a pore-broadening phenomenon at elevated temperature regions. Regeneration cycle testing demonstrated beta zeolite activity maintained stable throughout a 280 h time-on-stream period.

Contribution of Ca and V to enhancing coking-resistance and stability of MoV/CaO-intercalated montmorillonite catalyst in deoxydehydration of glycerol

Glycerol can be converted to allyl alcohol via deoxydehydration using molybdenum-vanadium, rhenium and iron based catalysts. However, the dehydration causes severe coking at strong acid sites on the surface of catalyst. Molybdenum-vanadium oxide supported on calcium oxide-intercalated montmorillonite (MoV-CaMMT) was prepared by oxalate anion intercalation followed by impregnation. MoV-CaMMT displayed the best catalytic performance of 86.5% glycerol conversion and good stability in 5 h. Correlating the results of XRD, XPS and TG analysis, it can be demonstrated that the addition of CaO in the catalyst preparation is conducive to the crystallization and dispersion of vanadium oxides, and reduces the acid strength, while the presence of a few vanadium dioxide and the stable conversion of V4+ and V5+ are the reasons for enhancing coking-resistance of MoV-CaMMT. Additionally, NH3-TPD analysis proved the coexistence of weak and strong acid sites in MoVOx, which are conducive to the formation of acetol.

Investigation on supported AlCl3 catalyst in the isomerization of E-1-chloro-3,3,3-trifluoropropene

By negative pressure sublimation, various supported AlCl3 catalysts were prepared and further applied in the gas-phase isomerization of (E)-1‑chloro-3,3,3-trifluoropropene at higher temperatures ranging from 250 °C to 330 °C. Among these, the 2.0 wt%AlCl3 supported on active carbon catalyst exhibited high catalytic activity within 44 h but was significantly deactivated from 44 h to 100 h. And the possible deactivation reasons of the AlCl3 catalyst were first revealed as the following aspects: 1) The loss of AlCl3; 2) The covering of active sites by fluorinated olefin polymerization; 3) The conversion of AlCl3 to AlClxF3-x (0 ≤ x ≤ 3) leading to the significant enhancement of strong acid sites. This work will pave the way for the subsequent development of AlCl3 catalyst suitable for high-temperature gas-phase reaction system.

Inhibitory effect of CO on NH3-SCR of NO over Mn/TiO2 catalyst at low temperature: Inhibitory mechanism investigated by in situ DRIFTS

The reaction of NO with NH3 over Mn/Ti catalyst in the presence of CO has been investigated at low temperature. CO can significantly decrease the NOx conversion between 100 and 300 °C and improve the N2 selectivity, especially above 200 °C. Besides, flue gas compositions reduce the CO oxidation due to the competitive adsorption among them. The XPS data suggested that surface chemical states of spent Mn/Ti catalyst in the presence and absence of CO did not vary obviously, pointing to that the surface chemical states of Mn/Ti catalyst don't account for the decrease in NOx conversion. The transient reactions and in situ DRIFTS experiments suggested that CO can compete with NO to adsorb on Mn/Ti catalyst and it can remarkably restrain NH3 to be adsorbed on weakly acid sites due to that these sites were occupied by carbonate species. This leads to the marked decrease in NOx conversion at low temperature and an increase in N2 selectivity because the amount of NH3 adsorbed on weakly acid sites decreases and it is mainly adsorbed on strong acid sites. In addition, the gaseous CO does not interfere with the reaction of gaseous NO with adsorbed NH3.

Study on the mechanism of sulfur poisoning in toluene catalyzed by Co3O4/γ-Al2O3 sulfur tolerant catalyst containing spinel structure

In this paper, in-situ thermal decomposition of ammonium sulfate method was used to cause sulfur poisoning of Co3O4/γ-Al2O3 catalyst rapidly and quantitatively. The pore structure, valence state of active species, surface morphology and acidity of the catalyst before and after sulfur poisoning were characterized, and its influence on catalytic combustion of toluene was studied. The results showed the crystal shape of the catalyst changed little after sulfur poisoning. As sulfur poisoning gradually deepened, the formation of sulfate blocked the pores, the high-valence cobalt decreased, strong acid sites increased, and its catalytic activity for toluene combustion gradually decreased. Formation of cobalt sulfate was a main reason for the decline in catalyst activity. Spinel phase CoAl2O4 formed outside γ-Al2O3 framework can adsorb a large amount of sulfur species to form sulfate, protecting Co3O4 and delaying the deactivation of catalysts.

Correlation between zeolitic particle size and the low-temperature NOx storage capacity of Pd/ZSM-11 passive NOx adsorber

The effect of zeolitic particle size on the NOx adsorption and desorption was investigated by synthesizing ZSM-11 zeolites with different particle sizes (0.5∼0.8, 1∼2, and 5∼6 μm) for doping Pd as passive NOx adsorbers (PNAs). Several characteristic techniques of XRD, HAADF-STEM, H2-TPR, CO-DRIFT, XPS and NH3-TPD were applied to clarify the essential association of the PNAs performance of Pd/ZSM-11 zeolites with the support zeolite properties and Pd active species. It was found that both the efficient Pd(II) species for assisting NOx adsorption-release and the acid amount (especially the strong acid sites) for facilitating Pd dispersion have positive correlation with the decrease of zeolite particle size. Differently, in addition to the active Pd species, meso-macroporosity properties are another key factors to determine the NOx adsorption ability of PNAs. The meso-macroporosity properties of Pd/Z11-1.5 show a negative correlation with the decrease of zeolite particle size while Pd/Z11-0.7's show the positive correlation with the decrease of zeolite particle size. As a consequence, Pd/Z11-1.5 with higher Pd(II) content but weaker meso-macroporosity properties than Pd/Z11-5.0 shows comparable adsorption capacity to Pd/Z11-5.0, while Pd/Z11-0.7 with both high Pd(II) content and good meso-macroporosity properties not only exhibits the highest NOx storage capacity, but also can release the NOx at the lowest temperature of less than 300 °C, indicating to be a good candidate for purifying NOx at the actual exhaust temperature of diesel vehicles.

Designing main-group catalysts for low-temperature methane combustion by ozone

The catalytic combustion of methane at a low temperature is becoming increasingly key to controlling unburned CH4 emissions from natural gas vehicles and power plants, although the low activity of benchmark platinum-group-metal catalysts hinders its broad application. Based on automated reaction route mapping, we explore main-group elements catalysts containing Si and Al for low-temperature CH4 combustion with ozone. Computational screening of the active site predicts that strong Brønsted acid sites are promising for methane combustion. We experimentally demonstrate that catalysts containing strong Bronsted acid sites exhibit improved CH4 conversion at 250 °C, correlating with the theoretical predictions. The main-group catalyst (proton-type beta zeolite) delivered a reaction rate that is 442 times higher than that of a benchmark catalyst (5 wt% Pd-loaded Al2O3) at 190 °C and exhibits higher tolerance to steam and SO2. Our strategy demonstrates the rational design of earth-abundant catalysts based on automated reaction route mapping.

Selective synthesis of 1,3-butadiene by vapor-phase dehydration of 1,4-butanediol over cerium oxide catalyst

Dehydration of biomass-derived 1,4-butanediol (1,4-BDO) is an attractive approach to synthesizing 1,3-butadiene (BD), which is a useful monomer for various polymers and currently produced via naphtha cracking. Cerium oxide (CeO2) with weak acid-base bifunctionality promoted the dehydration of 1,4-BDO to BD in 66% yield with 80% selectivity under the optimized conditions. The selectivity given by the CeO2 catalyst was influenced by the calcination temperatures, since the acid-base bifunctionality and reducibility of CeO2, which were examined temperature-programmed analyses, were altered. In stark contrast, the catalysts with strong acid sites exemplified by SiO2-Al2O3 and H-type mordenite (H-MOR) were inappropriate for this reaction since they produced tetrahydrofuran as a major product. The control experiments using a set of substrates suggested that 3-butene-1-ol was the main intermediate in the 1,4-BDO-to-BD dehydration, and its isomer of 2-butene-1-ol was also involved in the reaction but rather triggered the undesired side reactions to form butyraldehyde and ketones.

MCM-22 zeolite-based system to produce jet fuel from the 1-hexene oligomerization

The oligomerization of light olefins is an alternative for generating clean liquid fuels. In this study, the MCM-22 zeolite featuring a partially disordered layered structure with framework combined 10 membered ring (10 MR) was discussed for 1-hexene oligomerization. MCM-22 and Y zeolite were compared to investigate the influences of the framework and acidity strength on the activity and yield in the 1-hexene oligomerization. The results indicated that the MCM-22 zeolite was an efficient catalyst for oligomerization compared to Y zeolite. The MCM-22 zeolite was characterized in detail by NMR, Py-FTIR, and TG analyses. The catalytic performance and deactivation properties of MCM-22 zeolite in the oligomerization reaction of 1-hexene were investigated. Structure–activity relationships were established through the kinetic study. Although the density of strong acid sites was essential for the oligomerization of 1-hexene, the presence of low pressure was also necessary for the formation of dimers. Thus, MCM-22 zeolite demonstrates a substantial improvement in initial conversion and catalyst lifespan for 1-hexene oligomerization.

Improvement of n-Butene Yield in Dimethyl Ether-to-Olefin Reaction Using Ferrierite Zeolite Catalysts

Various ferrierite zeolites were investigated as catalysts for the dimethyl ether (DME)-to-olefin (DTO) reactions to efficiently synthesize n-butene, such as 1-butene, trans-2-butene, and cis-2-butene except for iso-butene using a fixed-bed flow reactor. Twenty P-loaded ferrierite zeolites with different structural parameters and acidic properties were prepared by the impregnation method by varying the P content and the temperature of air calcination as a pretreatment. The zeolites were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and NH3 temperature-programmed desorption (NH3-TPD). Micropore surface area, external surface area, total pore volume, micropore volume, and weak and strong acid sites affected the DTO reaction behavior. A high n-butene yield (31.2 C-mol%) was observed, which is higher than the previously reported maximum yield (27.6 C-mol%). Multiple regression analysis showed that micropore surface area and strong acid sites had a high correlation with n-butene yield. Based on our findings, we explained the reaction mechanism for selective n-butene synthesis except for iso-butene in the DTO reaction by the dual cycle model.

Features of the deactivation of Mg/HZSM-5 catalysts for the synthesis of lower olefins from dimethyl ether in a slurry reactor

In a slurry reactor, the formation of compaction products on Mg/HZSM-5 catalysts, irrespective of the SiO2 /Al2O3 molar ratio in the zeolite, proceeds predominantly on strong acidic sites. The composition of compaction products (mostly trimethyl- and tetramethylbenzenes) virtually does not change with a growth of the molar ratio; however, their amount decreases, which is related to a growth of the mesopore volume with an increase in the SiO2 /Al2O3 ratio. This leads to a decrease in diffusion limitations and contribution of secondary reactions and enhances the removal of coke precursors from the zeolite surface, thus promoting the catalyst activity (the conversion of DME increases twofold). The composition of reaction products changes only slightly with a growth of the SiO2 /Al2O3 molar ratio, the total selectivity to lower olefins is ca. 70 wt.%. A rapid loss of the Mg/HZSM-5 activity with extending the operation time in a slurry reactor is caused not by coking, but rather by «clogging» of the catalyst with decomposition products of the dispersion medium (polydimethylsiloxane).

HPW supported on ammonium hexafluorosilicate modified Hβ: Efficient catalysts for ethylene glycol and methyl tert‐butyl ether reaction with high selectivity and stability

A series of HPW supported on ammonium hexafluorosilicate (AHFs) modified Hβ (30HPW/Hβ‐Si(x)) was successfully prepared. After Hβ zeolite was pretreated with 0.1 mol·L−1 AHF's solution, the Brønsted/Lewis ratio of Hβ‐Si(0.1) increased compared with those of Hβ, and the strong acid density of 30HPW/Hβ‐Si(0.1) decreased compared with those of 30HPW/Hβ respectively. Strong acidic sites and Lewis acid sites are catalytic sites for by‐products diisobutene and ethylene glycol oligomers, which deposited on the catalyst result in the deactivation of catalysts. According to the results of characterization, the internal Si‐OH groups of Hβ (strong acidity sites) were filled with silicon of AHFs. The extraframework aluminum (strong acid sites) was removed by the H+, which is the hydrolysis of AHFs. In addition, the hydrophobicity of 30HPW/Hβ‐Si(0.1) was also improved compared with that of 30HPW/Hβ due to the SiO2/Al2O3 ratio of Hβ increased after treatment by 0.1 mol·L−1 AHFs solution. The 30HPW/Hβ‐Si(0.1) maintained an 80% conversion of methyl tert‐butyl ether and 100% selectivity to ethylene glycol mono‐tert‐butyl ether and DBE ethylene glycol bis‐tert‐butyl ether with 336 h of time on stream.

Boosting Conversion of CO2 to Light Olefins over MgO-Promoted ZnZrO/SAPO-34 Bifunctional Catalyst

CO2 hydrogenation to produce light olefins is a hopeful route to the cyclic utilization of CO2. Although metal oxide/zeolite bifunctional catalysts show outstanding performance for CO2 hydrogenation to olefins, they still expect to further improve its performance. Here, a ternary metal oxide solid solution catalyst by incorporating MgO into ZnZrO to adjust the acid and redox active sites and coupled with SAPO-34 zeolite (noted as Mg-ZnZrO/SAPO-34) was developed. The Mg-ZnZrO/SAPO-34 catalyst exhibits light olefins yield of 5.7% that higher than those of ZnZrO/SAPO-34 catalyst (4.5%) at 390 °C. The results discovered that the introduction of MgO can neutralize the strong acid site of zeolite and generate more oxygen vacancies, and exhibit superior ability to adsorb and activate CO2 and H2. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrate that carbonate formation by CO2 adsorption of doped MgO and participation in the reaction to form more HCOO* and CH3O* species on the Mg-ZnZrO/SAPO-34 catalyst. The strategy via adjusting the acid intensity and the content of oxygen vacancies developed in this work supplies a guideline to design high-performance catalysts for CO2 utilization.

Effect of Zn Contents of W/Zn-Beta Catalysts on Their Catalytic Performance in the Selective Hydrocracking of Tetrahydronaphthalene into Benzene, Toluene, and Xylene

Selective hydrocracking (HDC) of tetrahydronaphthalene (THN) into light aromatic hydrocarbons, such as benzene (B), toluene (T), and xylene (X), was performed over bifunctional catalysts with different ZnO contents (W/Zn-Beta) at 400 °C and 6 MPa. In this work, the change of catalytic performance of the bifunctional catalysts with different ZnO contents in selective HDC of THN and the nine-lump reaction kinetic model was investigated. It was found for the first time that ZnO can not only effectively regulate the acid properties of Beta zeolite but also react with WO3 to form non-active ZnWO4 crystals, resulting in low HDC activity of the catalyst. At low ZnO contents of the catalyst (<1 wt %), as the interaction of ZnO–Beta is stronger than that of WO3–Beta, the interaction of ZnO–Beta would replace the interaction of WO3–Beta, leading to the agglomeration of WO3 and the dispersions of WO3 on Beta zeolite decrease. As a result, WO3 would be easily reduced to WS2, and the BTX selectivity would increase. At high ZnO contents of the catalyst (≥1 wt %), the strong acid sites of Beta zeolite would be covered by ZnO. In addition, the excess ZnO would react with WO3 to form non-active ZnWO4 crystals, and the BTX selectivity would decrease. The W(25)/Zn(1)-Beta-40 catalyst exhibited maximal BTX selectivity (45 wt %) at 94% THN conversion. The kinetic study further indicated that with the increase of ZnO contents, the ratio of formation reaction rate of BTX to the over-HDC rate of BTX increases first and then decreases, and the reaction path selectivity of THN isomerization increases.

Dry reforming of methane using bimetallic Pt–Ni/Ti-SBA-15: Effect of Si/Ti ratio on catalytic activity and stability

A one-pot hydrothermal technique was used to make a series of Ti-incorporated mesoporous SBA-15 with varying Si/Ti ratios. The synthesized mesoporous materials were modified by introducing Ni (9%) as active metal and Pt (0.5%) as promoter using nickel nitrate and chloroplatinic acid, respectively, as metal precursors through incipient wetness impregnation method. All the catalysts and supports were characterized by X-ray diffraction, BET surface area, Fourier Transform–Infrared spectroscopy, UV–Visible diffuse reflectance spectroscopy, H2–temperature-programmed reduction, NH3–temperature-programmed desorption, transmission electron microscopy, and thermogravimetric analysis. The catalysts were subjected to dry reforming of methane using CH4/CO2 (molar feed ratio of 1:1) with a gas hourly space velocity (GHSV) of 36,000 mL. g−1. h−1 at a temperature range of 400–800 °C. The characterization results confirmed the incorporation of titanium ions in the SBA-15 matrix. However, Si/Ti loadings of 10 and 20 exhibited low extra-framework anatase phase titania levels, and high surface acidity. Among the subjected catalysts, Pt–Ni/Ti-SBA-15 (Si/Ti = 10) showed higher catalytic activity (CH4 = 84% and CO2 = 91%) with a H2/CO ratio of 3.6 after an 8 h reaction, and exhibited higher stability and coke tolerance than the bare catalysts and other modified Pt–Ni/Ti-SBA-15 catalysts. The characterization results of spent catalysts also confirmed low coke deposition on titanium-incorporated catalysts. The remarkable performance of the Pt–Ni/Ti-SBA-15 towards CH4 conversion and CO2 conversion may be related to strong metal–support interaction, presence of strong and weak acid sites, well-dispersed active metals and bi-metallic interaction.