Hammett Indicator Research Articles

Sorption of cesium by aluminosilicate sorbents from rice straw

Using rice straw of various varieties of the Far Eastern selection as a source of silicon, a number of samples of sodium aluminosilicates with a Si:Al ratio from 1.02 to 1.56 were synthesized. For the obtained samples, the elemental and phase composition was found, the thermal properties were investigated. The morphology of aluminosilicates was studied: the particle size varies from 0.2 to 50 μm with a maximum distribution of about 10 μm, the specific surface area is 364 m2/g. The acid-base properties of the surface of aluminosilicates are characterized by pH-metry methods and the Hammett indicator method, the nature of the distribution of adsorption centers on the surface is established. The sorption capacity of the obtained samples, determined with respect to methylene blue (MB), is from 31.9 to 103.9 mg/g. By varying the synthesis conditions, it was shown that the greatest sorption capacity with respect to MB is achieved at the time of hydrolysis of the original rice straw for 60 minutes. It is shown that the sorption of Cs+ ions in the obtained samples is described by the Langmuir model. The sorption properties with respect to Cs+ ions from aqueous solutions with different salt background were studied.

Synthesis of CaO[sbnd]SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil

The powder mixtures of calcium oxide (CaO) and silica gel (SiO2) in molar ratios of 1:1, 1.5:1, 2:1 and 3:1 were mechanochemically treated with the addition of water, and were subsequently calcined with a goal of synthesizing CaSiO3, Ca3Si2O7, Ca2SiO4 compounds and CaO/Ca2SiO4 two-phase mixture. The prepared materials were characterized by XRD, FTIR, SEM/EDS, particle size laser diffraction (PSLD), UV–vis diffuse reflectance spectroscopy (DRS), N2 adsorption/desorption isotherms, Hammett indicator for basic strength and volumetric analysis for free CaO content. The catalytic activity of calcium silicates with different Ca/Si ratios was tested in the transesterification of triacylglycerols (sunflower oil) with methanol. Samples obtained with initial composition 2CaO·SiO2 and 3CaO·SiO2 calcined at 700 °C, and 3CaO·SiO2 calcined at 900 °C had high catalytic activity, resulting with triacylglycerols conversion and fatty acids methyl ester formation (FAME or biodiesel) above 96%. The activity of these samples can be attributed to the existence of free CaO defined by CaO/Ca2SiO4 complex mixture. The effect of different amount of catalyst used for transesterification (0.2–2 wt%) was analyzed using the most active catalyst i.e. 3CaO·SiO2 calcined at 700 °C as well as possibility of its reuse for biodiesel synthesis. It was also found that CaSiO3, Ca3Si2O7 and Ca2SiO4, phases did not possess catalytic activity.

Nano-magnetic potassium impregnated ceria as catalyst for the biodiesel production

The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe3O4-CeO2 nanocatalyst. The various concentration of potassium impregnated Fe3O4-CeO2 was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe3O4-CeO2 nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reaction temperature for transesterification reaction was analyzed and yield was determined by 1H NMR. The maximum yield of 96.13% was obtained at 4.5 wt % catalyst amount, 1:7 oil to methanol ratio at 65 °C for 120 min. The properties of biodiesel such as acid value and kinematic viscosity were observed as 0.308 mg KOH/g and 4.37 mm2/s respectively. The other fuel parameters such as flash point and density were also determined. The reusability of catalyst was observed and it showed stability up to five cycles without considerable loss of activity. The recovery of excess methanol after transesterification reaction was achieved using distillation process setup.

Tamarindus Indica fruit shell ash: a low cost and effective catalyst for biodiesel production from Parinari curatellifolia seeds oil

The study evaluated the potential use of agricultural waste, Tamarindus indica fruit shell ash, as a solid base catalyst for production of biodiesel. The catalyst was prepared by calcination of T. indica fruit shell at 800 °C in muffle furnace for 3 h. Branauer-Emmett-Teller, thermal gravimetric analysis, X-ray diffraction, scanning electron microscope, X-ray florescence, and Hammett indicator techniques were used to characterize the physicochemical properties of the produced catalyst. The catalyst had basic strength of greater than 9.7 and mesoporous structure with pore size d = 3.2 nm. The crystalline phase was made up of calcium oxide, potassium oxide, and magnesium oxide. The catalyst was tested for biodiesel production using Parinari curatellifolia seeds oil. The results showed that the best operating parameters for the production of biodiesel were 9:1 methanol to oil molar ratio, 125 mg catalyst (5 wt% of oil), 2 h reaction time, and 60 °C reaction temperature. These optimized operating parameters afforded a maximum yield of 96.2%. Also, fuel properties of biodiesel: acid value, viscosity, and flash, pour, and cloud points were investigated and compared to the ASTM standards limits D6751. The results were observed to be in good agreement with the ASTM standards limits for biodiesel. In addition, the catalyst was easily separated and subsequently reused for four runs in biodiesel production. Thus, Tamarind fruit shell derived catalyst is very promising for the production of biodiesel due to its high performance, low-cost, easy preparation and availability.

Solid catalysts obtained from wastes for FAME production using mixtures of refined palm oil and waste cooking oils

More than 95% of biodiesel production feedstocks come from edible oils, however it may cause some problems such as the competition of land use between food production and biodiesel production. The waste cooking oils (WCO) are an alternative feedstock for biodiesel production; its usage reduces significantly the cost of biodiesel production and has environmental benefits, e.g., a waste recovery instead of its elimination. This work aims to produce a low-cost efficient solid catalyst for fatty acid methyl esters (FAME) production using mixtures of refined palm oil (RPO) and WCO. Four low cost catalysts were prepared (biomass fly ashes, natural dolomite rock, chicken eggshells and polyethylene terephthalate - PET), characterized (by SEM, EDX, XRD, BET, FT-IR and Hammett indicators) and tested regarding their performance in FAME production. The maximum yield of FAME achieved was around 96%wt. for biomass fly ashes catalyst at 60 °C, 9:1 (mol/mol) of methanol to oil mixture, 10%wt. catalyst to oil mixture, over 180 min in batch reactor. The results point out for promising bifunctional catalysts able to achieve also conversion of free fatty acids up to 100% using mixtures of RPO and WCO.

Can Hammett indicators accurately measure the acidity of zeolite catalysts with confined space? Insights into the mechanism of coloration

The acidic properties of zeolite catalysts play a crucial role in governing catalytic performances, which makes the acidity characterization an important subject in the field of zeolite catalysis.

Utilization of bifunctional catalyst for upgrading petroleum residue via cracking and gasification: Effect of catalysts

Vacuum residue is stepwise and high-efficient converted by the base cracking and coke gasification process. Cracking effect of vacuum residue was carried out with different bifunctional catalysts in a fluidized bed reactor, respectively. Calcium aluminate catalyst specialized for cracking and gasification procedure is selected with the activities of cracking and gasification. In comparison with silica sand, calcium aluminate catalyst showed the higher vacuum residue cracking activity, and cracking activity gradually increased with increasing the Ca/Al ratios. The results indicated that C2C4 olefinicity of above 60.4%, cracking-generated coke of about 5.0 wt%, and light oil yields is over 84.0 wt% at 650 °C with a catalyst-to-oil ratio of 7.0. Moreover, it was also found that calcium aluminate catalyst synthetized with the Ca/Al molar ratio of 12:7 and carbon black as pore-forming agent displayed a better cracking properties than that of the other catalysts. VR cracking properties over calcium aluminate catalysts was closely related to their basicity, as indicated by the Hammett indicators method. Cracking-generated coke on the base catalyst was well gasified with pure steam at 800 °C and produced the syngas with the total content of H2 and CO2 up to 81.5 vol%, the coke conversion over the tested catalysts is of above 93.6% in 30 min. Also, the alternating base cracking and gasification operations were performed three times to verify the stability of the optimal calcium aluminate catalyst. The selected catalysts presented high hydrothermal stability and stable cracking activity, which could be potentially used for vacuum residue stepwise and high-efficient utilization via vacuum residue catalytic cracking and gasification regeneration process.

Catalytic performance of strontium oxide supported by MIL–100(Fe) derivate as transesterification catalyst for biodiesel production

Strontium oxide (SrO) is restricted by poor reusability and pore structure in catalyzing transesterification for biodiesel production. To address this problem, metal organic frameworks is employed as a carrier to support strontium carbonate by mechanical mixing method (MM) and in situ titration method (ST), and then calcined under inert atmosphere to obtain the catalyst of MM–SrO and ST–SrO. As a comparison, the reusability of pure SrO is compared and the homogeneous contribution of leached active sites for ST–SrO and MM–SrO are also assessed. The catalysts are characterized by TG, XRD, FTIR, EDS, Hammett indicator titration, nitrogen adsorption–desorption, and VSM. From the catalyst reusability, MM–SrO exhibits the excellent performance, where the maximum conversion of 96.19% is achieved at molar ratio of methanol to oil 12, catalyst addition 8 wt% (refer to oil), reaction temperature 65 °C within 30 min. And the conversion of 82.49% is still obtained at the third cycle, which could be easily separated from the mixture by external magnetic field after each cycle as well. In order to optimize the activation condition and investigate MM–SrO deeply, thermal characteristics of its corresponding precursor are further evaluated, where the TG experiments are conducted at heating rate of 20, 30, and 40 °C/min. and kinetic parameters are calculated through model–free method and Avrami theory, respectively.

Assessment the activity of magnetic KOH/Fe3O4@Al2O3 core-shell nanocatalyst in transesterification reaction: effect of Fe/Al ratio on structural and performance.

Recently, biodiesel production using heterogeneous catalysts has been of great concern. However, simple separation of these catalysts from product mixtures is a problem of the process. In this study, series of magnetic KOH/Fe3O4@Al2O3 core-shell nanocatalysts were synthesized via the incipient wetness impregnation method and the effect of weight ratio of Fe3O4-to-Al2O3 (0.15-0.35) on the catalytic performance was assessed. The samples were characterized by XRD, FTIR, BET-BJH, VSM, SEM, TEM, and EDX analyses and their basicity was measured by the Hammett indicator method. The results revealed that although the magnetic KOH/Fe3O4@Al2O3 nanocatalyst with 25wt% of Fe3O4 showed less activity as compared to those with 15wt% of Fe3O4, it exhibited higher surface area and appropriate magnetic properties. The sample presented superparamagnetic properties with the magnetic strength of 1.25emu/g that was simply recovered by using an external magnetic field. The nanocatalyst converted 98.8% of canola oil to biodiesel under reflux condition at the best operational conditions of 12M ratio of methanol/oil, 4wt% of catalyst and 6h of reaction time. Moreover, the nanocatalyst showed high reusability such that it was reused several times without appreciable loss of its catalytic activity.

Green synthetic methodology: An evaluative study for impact of surface basicity of MnO2 doped MgO nanocomposites in Wittig reaction

For synthesis of flavoring agent E-ethyl cinnamate in an economic way using Wittig reaction, MnO2 doped MgO nanocomposites were prepared by alkali leached hydrothermal method. The resultant nanocomposites were characterized by XRD, UV-DRS, FT-IR, FESEM, EDAX, XPS and Hammett indicator method. This surface modified MnO2 doped MgO can be used as green solid base for Wittig reaction between benzaldehyde and phosponium salt for synthesis of E-ethyl cinnamate under solvent free approach. Nanocomposite of MgO with MnO2 in combination with green mechanochemical approach seems to be more economic in comparison to pure nanosized MgO under conventional solvent stirring. Both efforts are complementary for promoting surface basic activity of MgO for high-yield synthesis of E-ethyl cinnamate using Wittig reaction. The product ethyl cinnamate has been characterized by HR-MS, IR, 1H NMR.

Alteration of the Acid-Base Properties of the Oxidized Surface of Disperse Aluminum during the Adsorption of Ammonium Compounds and the Antifriction Effect

The number of active centers of disperse aluminum powder is determined by the spectrophotometric method using the Hammett indicators in the range of pKa values of 0.3 to 14.2; alteration of the distribution of the donor-acceptor sites on the surface as a result of the adsorption of quaternary ammonium compounds (QACs) from the gas phase is studied. The curves of the distribution of adsorption sites of aluminum-based powders are built depending on the ionization constant pKa of the indicators. A sharp decrease in the number of active sites in the Lewis acid sites region is detected for Al/(A + T) sample, where alkamon (A) and triamon (T) are jointly adsorbed. The number of sites is halved at pKa =–0.3, 5, and 9.5. We reveal that the antifriction effect of a lubricant is enhanced as the acidity of the surface of the powder with the adsorbed quaternary ammonium compounds is decreased.

Influence of calcination temperature on the activity of mesoporous CaO/TiO2\u2013ZrO2 catalyst in the esterification reaction

In the present study, the effect of calcination temperature on the structure and performance of mesoporous CaO/TiO2–ZrO2 catalyst fabricated by sol–gel method used in the esterification reaction was assessed. Then, CaO/TiO2 catalyst was also synthesized via the same method to evaluate the effect of zirconia cations on its properties and activity. The samples were characterized by X-ray Diffraction (XRD), Fourier transmittance infra-red (FT-IR), Brunauer–Emmett–Teller (BET)–Barrett-Joyner-Halenda (BJH), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analyses. Moreover, Hammett indicator method was utilized to assess the acidity and basicity of the samples. It was found that zirconium was clearly incorporated in CaO/TiO2 lattice and transformed that from amorphous phase to crystalline structure. In addition, the basicity and acidity of CaO/TiO2 was clearly increased by zirconia loading. Evaluation of the samples’ activity presented that CaO/TiO2 catalyst exhibit no activity in the esterification reaction, while all CaO/TiO2–ZrO2 catalysts showed high ability to convert oleic acid to its ester. Moreover, the catalyst calcined at 400 °C showed the highest activity in the esterification reaction with desirable properties such as high crystallinity, acidity, basicity and surface area along with well-distribution of particle size and pore size. The best catalyst converted around 90% of oleic acid to ester at optimized conditions of 150 °C, 12:1 molar ratio of methanol/oleic acid, 3 wt% of catalyst for 4 h of reaction time. Moreover, the sample was successfully used for five runs without significant reduction in activity that makes it a suitable choice as a catalyst for industrial applications.Graphical abstract

Waste cooking oil and waste chicken eggshells derived solid base catalyst for the biodiesel production: Optimization and kinetics

Waste chicken eggshells were used to derive two catalysts labeled in this study as Eggshell-CaOC-H-D and Eggshell-CaDG. Both these catalysts were characterized by FTIR, XRD, BET, SEM, and basic strength was determined by the Hammett indicator method. The transesterification of waste cooking oil was carried out to compare the catalytic activity of Eggshell-CaDG and Eggshell-CaOC-H-D. The effect of various reaction parameters-methanol molar ratio, temperature, speed of agitation, and catalyst loading on the progress of the reaction was also tested to produce higher biodiesel yield. Eggshell-CaDG catalyzed reaction produced 96.07% biodiesel under the optimized reaction conditions of methanol molar ratio 10:1, catalyst loading 1.50 wt%, temperature 60 °C and speed of agitation 300 rpm with a reaction time of 50 min. Whereas, Eggshell-CaOC-H-D was yielded 93.10% biodiesel for the optimized operating parameters-methanol molar ratio 12:1, 400 rpm, 65 °C, catalyst loading of 3 wt% in the reaction time of 90 min. The reusability for both the catalysts was tested up to five cycles and found that biodiesel yield was decreased with successive cycles. The activation energies of the Eggshell-CaDG and Eggshell-CaOC-H-D were found to be 31.39 and 54.05 kJ mol−1, respectively. The physicochemical properties of the biodiesel were also found as per the ASTM standard range.

Biodiesel production by a highly effective renewable catalyst from pyrolytic rice husk

High efficiency and stable CaO-based catalysts which used rice husk biochar as a carrier were utilized to catalyze transesterification of vegetable oil with methanol. The properties of the synthesized catalyst were determined using XRD, TGA, FT-IR, SEM, EDX, N2 adsorption/desorption, XPS and the Hammett indicator method. The influences of catalyst preparation, reaction parameters and reusability of catalyst were also investigated. The results indicated that the catalyst activity mainly depended on the pretreatment temperature, structure and basicity of the catalysts. The maximum yield could reach 93.4% under the prepared conditions of 30% CaO loading and 700 °C calcination temperature. Meanwhile, after being reused for 10 cycles, there was no noticeable loss of catalyst activity in biodiesel yield (above 85%). The appearance of CaOSi bond on the catalyst surface was the main reason for high stability. The findings suggested that the rice husk biochar based catalyst was a very promising choice for biodiesel production.

Potential of using ceramics wastes as a solid catalyst in biodiesel production

Abstract Reusing waste products is one of the milestones of progress toward environmental sustainability; producers can add value by reusing waste products. This study reports that ceramics wastes (CWs) are suitable raw materials for preparing a solid-base catalyst for biodiesel production. This study synthesized biodiesel from soybean oil using transesterification over a CWL-800-2. CWL-800-2 can be used directly for biodiesel production without being further dried or thermal pretreated, avoiding the usual activation of solid catalysts at high temperature. The effects of the calcination temperature and duration, methanol/oil ratio and catalyst amounts on the conversion are also reported in this paper. The solid base catalyst was highly active, air‐insensitive and can be reused for at least four cycles without loss of activity. The catalysts were characterized using XRD, FE-SEM, FTIR, BET and the Hammett indicator method.

Transesterification of non-edible oils over potassium acetate impregnated CaO solid base catalyst

Biodiesel production through transesterification reaction with methanol using calcium oxide (CaO) as a solid base catalyst is restricted due to the need to the high molar ratio of methanol to oil and long reaction time. Therefore, the CaO catalyst was modified by potassium acetate (PA) to prepare PA/CaO solid base catalyst via wet impregnation method. X-ray Diffraction, Scanning Electron Microscopy, Thermal Gravimetric Analysis, Fourier Transform Infra-Red spectroscopy, Hammett indicator (basic strength), and the Inductive Couple Plasma techniques, were applied to characterize the prepared catalyst. The effect of the PA ratio loaded on CaO and calcination temperature were investigated as well. The catalyst activity was tested through transesterifcation reaction of non-edible oils, namely bitter almond oil BAO and waste fish oil WFO, with methanol. Transesterifcation process was optimized through the parameters involving the solid catalyst amount, methanol to oil molar ratio, reaction temperature, and reaction time. The highest methyl ester yield from both BAO (91.22 wt%) and WFO (93.30 wt%) were achieved by employing 2.0 wt% , and 1.0 wt% of PA/CaO catalyst, respectively, 9:1 methanol to oil molar ratio, 60 °C reaction temperature, and 120 min reaction time. The prepared catalyst was retrievable and thermally stable giving a yield up to 75 wt% after a 4th cycle reuse. The fuel properties of the raw oils were significantly enhanced as a result of transesterification, and were in conformity with the ASTM D 6751 limits. Conversion of the non-edible oils to biodiesel using the catalyst was confirmed by 1H NMR spectroscopy which gives yield percent close to those of the practically obtained. Moreover, the FTIR spectroscopy assured the conversion of the non-edible oils into biodiesel. As such, PA/CaO composite may be considered as a promising solid base catalyst for transesterification of non-edible oils with methanol.

Influence of acid-base and adsorptive characteristics of disperse aluminum modified by ammonium compounds on antifriction effect in lubricant

The article analyses the acid-base and adsorptive characteristics of the metal samples obtained using method of layering of different-sized molecules of quaternary ammonium compounds (QAC). The method allows to vary the hydrophilic-lipophilic, antifriction and other properties of commonly used disperse metals. The method includes the process of adsorption of reagents such as QAC based triamon (C1-C2) and alkamon (C16-C18), which have very different in length hydrocarbon radical at nitrogen atom. The acid-base properties of modified disperse aluminum were studied using Hammett indicator method and it has been established that there is a change in the quantity of the donor-acceptor centers of the powder caused by the adsorption of QAC. Spectrophotometric analysis of surface centers was performed using the Hammett indicators within the range of pKa values from -0.3 to 14.2. The distribution curves of the active adsorption centers of aluminum-based powders were plotted against the acid dissociation constant (acid strength - pKa) of the indicators. A sharp decrease is observed in the number of centers in the Lewis acid sites region for the Al/(A+T) sample with co-adsorbed alkamone (A) and triamon (T). In addition, significant decrease in antifriction and water-repellent properties of the sample Al/T/A (consistent treatment of metal in vapor of T and A) in comparison with sample Al/(A+T) is explained by the increase of Bronsted base centers with pKa = 9.5 and less intense interaction of QAC with Lewis acid centers with pKa = 14.2.The following pattern was revealed: increase in the antifriction effect of oil based lubricants is accompanied by reduction of the Bronsted centers content and as a rule by the decrease of acidity function (H) of the surface of the QAC-modified Al-powder which was added to the lubricant.

Comparative Study of Potassium Salt-Loaded MgAl Hydrotalcites for the Knoevenagel Condensation Reaction.

A series of potassium salt-loaded MgAl hydrotalcites were synthesized by wet impregnation of KNO3, KF, KOH, K2CO3, and KHCO3 salts over calcined MgAl hydrotalcite (Mg–Al = 3:1). The samples were characterized by X-ray diffraction, Fourier transform infrared, thermogravimetry–differential thermal analysis, scanning electron microscopy, and N2 absorption–desorption techniques to investigate their structural properties. The results showed formation of well-developed hydrotalcite phase and reconstruction of layered structure after impregnation. The prepared hydrotalcites possess mesopores and micropores having pore diameters in the range of 3.3–4.0 nm and Brunauer–Emmett–Teller surface area 90–207 m2 g–1. Base strengths calculated from Hammett indicator method were found increasing after loading salts, where KOH-loaded hydrotalcite showed base strength in the range of 12.7 < H– < 15, which was found to be the preferred catalyst. Subsequently, KOH loading was increased from 10 to 40% (w/w) and catalytic activity was evaluated for the Knoevenagel condensation reaction at room temperature. Density functional theory calculations show that among all of the oxygen atoms present in the hydrotalcite, the O atom attached to the K atom has the highest basic character. In this study, 10% KOH-loaded hydrotalcite showing 99% conversion and 100% selectivity was selected as the preferred catalyst in terms of base strength, stability, and catalytic efficiency.

Synthesis of calcium materials in biochar matrix as a highly stable catalyst for biodiesel production

Abstract In this study, the biochar which was obtained from peat was modified and served as the support for the preparation of cost-effective solid base catalysts for the transesterification reaction. The composition, structure and texture of prepared catalysts were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), N2 adsorption/desorption, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and the Hammett indicator method. It was found that the surface area and pore volume of the peat biochar were increased significantly (from 80.25 m2/g and 105.36 mm3/g to 230.86 m2/g and 296.23 mm3/g, respectively) by chemical activation treatment with KOH. The best performance is observed for the resulting 30Ca/APB-700 catalyst (30% CaO loading and 700 °C calcination temperature), and over biodiesel yield of 93.4% was achieved at catalyst amount of 5 wt.%, methanol/oil molar ratio of 8:1 and reaction time of 150 min. Besides, after reused for 10 cycles, the catalytic efficiency had a slight deactivation in biodiesel production (above 81.6% of yield obtained). The high stability of catalyst was mainly attributed to the formation of Ca O Si bond on the catalyst surface.

Mesoporous Titanium-Silicalite Zeolite Containing Organic Templates as a Bifunctional Catalyst for Cycloaddition of CO2 and Epoxides.

Mesoporous TS-1 (MTS-1) containing organic templates tetrapropylammonium hydroxide (TPAOH) and polydiallyldimethylammonium chloride is synthesized and treated with different concentrations of hydrochloric acid aqueous solution. The as-synthesized MTS-1 are characterized using X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy, transmission electron microscopy, UV-vis, 13C cross-polarization/magic angle spinning (CP/MAS) NMR, thermogravimetry analysis, CO2-temperature-programmed desorption (TPD), N2 adsorption-desorption, X-ray fluorescence, and elemental analysis. The results of 13C CP/MAS NMR show that the structures of organic templates are retained after acid washing treatment. Not required to be removed by calcination, the organic templates embedded in MTS-1 can take the role of basic sites and activate carbon dioxide (CO2), which is confirmed by FT-IR. Moreover, the amount of acid sites and basic sites in the samples before and after acid treatment is characterized by modified Hammett indicator method and CO2-TPD, respectively. The results show that both the acidity and the basicity in the material are improved after acid washing. Thus, the sample after acid treatment contains two active sites: basic sites stemming from organic species and acid sites coming from framework Ti, which is beneficial to be used as a bifunctional catalyst in the cycloaddition reaction of CO2 and epoxides. It is highly active in the cycloaddition reaction, in which the conversion of epichlorohydrin (ECH) could reach 97.8% and the selectivity of cyclic carbonate is 98.0% under 1.6 MPa at 393 K for 6 h when acetonitrile is used as a solvent. Moreover, the kinetics of the cycloaddition reaction are studied using ECH as a substrate by varying the reaction parameters. More importantly, the organic-inorganic hybrid catalyst is reusable and stable against leaching of organic species in the cycloaddition reaction.