Advancements in TiO2-based photocatalysis for environmental remediation: Strategies for enhancing visible-light-driven activity

Researchers have focused on efficient techniques for degrading hazardous organic pollutants due to their negative impacts on ecological systems, necessitating immediate remediation. Specifically, TiO2-based photocatalysts, a wide-bandgap semiconductor material, have been extensively studied for their application in environmental remediation. However, the extensive band gap energy and speedy reattachment of electron (e-) and hole (h+) pairs in bare TiO2 are considered major disadvantages for photocatalysis. This review extensively focuses on the combination of semiconducting photocatalysts for commercial outcomes to develop efficient heterojunctions with high photocatalytic activity by minimizing the e-/h+ recombination rate. The improved activity of these heterojunctions is due to their greater surface area, rich active sites, narrow band gap, and high light-harvesting tendency. In this context, strategies for increasing visible light activity, including doping with metals and non-metals, surface modifications, morphology control, composite formation, heterojunction formation, bandgap engineering, surface plasmon resonance, and optimizing reaction conditions are discussed. Furthermore, this review critically assesses the latest developments in TiO2 photocatalysts for the efficient decomposition of various organic contaminants from wastewater, such as pharmaceutical waste, dyes, pesticides, aromatic hydrocarbons, and halo compounds. This review implies that doping is an effective, economical, and simple process for TiO2 nanostructures and that a heterogeneous photocatalytic mechanism is an eco-friendly substitute for the removal of various pollutants. This review provides valuable insights for researchers involved in the development of efficient photocatalysts for environmental remediation.

Compositional dependence of Co- and Mo-supported beta zeolite for selective one-step hydrotreatment of methyl palmitate to produce bio jet fuel range hydrocarbons

For producing a drop-in bio jet fuel, one-step hydrotreatment, which includes deoxygenation, isomerization and cracking in one step, is essential to overcome the typical biofuel drawbacks due to high oxygen content, out of jet fuel range hydrocarbons, and low isomerization degree. Herein, Co- or/and Mo-supported Beta(25) zeolites with various Co/Mo ratios were prepared as transition metal-supported zeolite catalysts without the need for sulfidation of conventional transition metal catalysts. Based on the catalyst characterization, the Co/Mo ratio alters the metal phase with the appearance of CoMoO₄ and the altered Co metal phase strongly influences the acidic properties of Beta(25) by the formation of Lewis (L) acid sites with different strengths as Co₃O₄ and CoMoO₄ for strong and weak L acid sites, respectively. The catalytic activities were investigated for hydrotreatment of methyl palmitate as a biofuel model compound of fatty acid methyl esters. Primarily, Co is required for deoxygenation and Mo suppresses overcracking to enhance the yield of jet fuel range hydrocarbons. The Co/Mo ratio plays an important role to improve the C₈-C₁₆ selectivity by modifying the acidic properties to inhibit excessive cracking. Co₅Mo₁₀/Beta(25) achieved the best catalytic performance with the conversion of 94.2%, C₈-C₁₆ selectivity of 89.7 wt%, and high isomer ratio of 83.8% in organic liquid product. This unique modification of acidic properties will find use in the design of optimal transition metal-supported zeolite catalysts for selective one-step hydrotreatment to produce bio jet fuel range hydrocarbons.

Effects of Steaming and SiO₂ Surface Passivation on SSZ-13 Zeolites in the Ethylene to Propylene Reaction

SSZ-13 zeolite was modified by two kinds of post-treatment methods such as steaming and SiO₂ surface passivation (silylation) for ETP catalyst with high activity. The former steaming treatment was conducted in the range of 400-700 °C, whereas the latter surfaces passivation was applied to a chemical liquid deposition (CLD) technique that uses various silylation agents such as tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), and tetrabuthylorthosilicate (TBOS). Catalysts were characterized by powder-XRD, ICP, Ar-phsisorption, solid-state ²⁷Al MAS NMR, and NH₃-TPD, and their activities were tested in fixed bed reaction system. Regarding the effects of steaming temperature, the results show that a relatively higher selectivity is observed in SSZ-13 catalysts treated at proper steaming temperatures such as 450 and 500 °C compared to parent and other steam treated catalysts. For optimum surface passivation treatments for ETP reactions, one-step surface passivation using TEOS agents among various passivation agents led to enhanced propylene selectivity to 80% when compared with parent and other silylated SSZ-13 catalysts. However, a sequential passivation treatment with a TEOS agent was not highly affected by the reaction activity.

Identification of transfusion-transmitted hepatitis A through postdonation information in Korea: results of an HAV lookback (2007-2012)

BACKGROUND AND OBJECTIVES

Despite safety measures to minimize the risk of transfusion-transmitted infections, a residual risk remains. To trace and review some such cases, we ask donors to notify the blood centre if they are diagnosed with an infection after they donate blood.

MATERIALS AND METHODS

We analysed all data on postdonation cases of hepatitis A reported between 2007 and 2012. Archived specimens from these donors were tested for hepatitis A virus (HAV) using anti-HAV IgM/IgG and HAV-PCR as markers. If any of the test results were positive, we reviewed the medical records of the recipients and, if necessary, tested them for hepatitis A.

RESULTS

Fifteen blood donors notified the blood centres of having been diagnosed with hepatitis A after donation. All archived samples except for one were HAV-PCR-positive and anti-HAV IgM/IgG-negative. Of the donated components, four RBCs and 14 FFPs had not been transfused to patients and were recalled. Among 26 recipients of the implicated components, fourteen were still alive when they were notified. Two patients showed clinical symptoms of hepatitis A and had positive results with anti-HAV IgM.

CONCLUSION

Transfusion-transmitted hepatitis A is rare but exists. To reduce the risk, donors should be told to notify the blood centre if they are diagnosed with blood-borne diseases after they donate blood. Physicians should consider the possibility of transfusion-transmitted hepatitis A if a transfused patient has hepatitis A but no history of travel or route of faecal-oral infection.

Ring Opening of Naphthenic Molecules Over Metal Containing Mesoporous Y Zeolite Catalyst

Mesoporous Y zeolite (Meso-Y) with a uniform mesopore was synthesized via pseudomorphic syn- thesis. The Meso-Y supported Ni-W catalyst (NiW/Meso-Y) was introduced as a catalyst for the selective ring opening of naphthenic rings. The catalytic test for the ring opening of naphthalene as a model compound of multi-ring aromatics was performed using a batch-type reaction system with both sulfided 20 wt% NiW/Meso-Y and NiW/Y catalysts under different reaction conditions. The catalytic results reveal that the Meso-Y supported NiW catalyst experiences a naphthalene conversion similar to the NiW/Y catalyst, but the NiW/Meso-Y catalyst has higher product yields for BTEX (benzene, toluene, ethyl benzene, and xylene) and the middle distillate than those of the NiW/Y catalyst at a low reaction temperature. These results suggest that the mesoporosity of the NiW/Meso-Y catalyst is more advantageous for the ring opening reaction of multi-ring aromatics due to the easier access for the bulky molecules compared to the NiW/Y catalyst.

Conversion to Aromatic Hydrocarbons Over Nano- and Micro-Sized Particle La/Zn/HZSM-5 Catalysts

The effect of the template of HZSM-5 and its synthesis method on the catalytic conversions of ethanol to aromatic hydrocarbons has been investigated over a 0.8%Zn/0.6%La/HZSM-5 (Si/Al2 = 50) catalyst in a fixed-bed flow reactor under operating conditions of T = 710 K, P = 1 bar, and WHSV = 0.8 hr(-1). Nano- and micro-size HZSM-5 were prepared by hydrothermal and microwave synthesis with different templates: TPAOH, TPABr, and HMDA. Zinc and lanthanum modified HZSM-5 catalysts were prepared by a simple co-impregnation method. It was found that the size of the particles and the crystal structure of HZSM-5 were influenced by the template type and synthesis method. When using the TPAOH template, the nano-sized particles were prepared by microwave synthesis, whereas HZSM-5 prepared from TPABr and HMDA by a hydrothermal method, were composed of cubic shaped nanocrystals inside a micro-sized particle. The effect of the template on the selectivity to aromatics over a La/Zn/HZSM-5 catalyst was shown as follows: HMDA > TPABr > TPAOH.

Catalytic conversion of cellulose over mesoporous Y zeolite

Mesoporous Y zeolite (Meso-Y) was applied, for the first time, to the catalytic pyrolysis of cellulose which is a major constituent of lignocellulosic biomass, to produce high-quality bio-oil. A representative mesoporous catalyst Al-MCM-41 was also used to compare its catalytic activity with that of Meso-Y. Pyrolysis-gas chromatography/mass spectrometry was used for the experiments. Meso-Y, with higher acidity, led to larger yields of aromatics and furans with high value-added than Al-MCM-41, resulting in the production of bio-oil with higher quality. The effect of temperature on the catalytic pyrolysis was not significant within the range of 400-500 degrees C. When the Meso-Y to cellulose ratio was increased from 1/1 via 2/1 to 3/1, the deoxygenation efficiency increased, leading to increased yield of aromatics.

Catalytic conversion of Undaria Pinnatifida over nanoporous materials using Py-GC/MS

Catalytic pyrolysis of Undaria Pinnatifida was carried out over a nanoporous Al-SBA-15 catalyst for the first time. Pt nanoparticles were added to Al-SBA-15 to generate a Pt/Al-SBA-15 catalyst. The effect of the addition of the Pt nanoparticles on the catalytic pyrolysis was investigated. For rapid product analysis and catalyst evaluation, a pyrolysis-gas chromatography/mass spectrometry was used. The characteristics of the catalysts were analyzed using X-ray diffraction, nitrogen adsorption-desorption, transmission electron microscope, NH3 temperature programmed desorption, and inductively coupled plasma optical emission spectrometer. Compared to the non-catalytic pyrolysis, catalytic pyrolysis over Al-SBA-15 produced a higher-quality bio-oil with a high stability and a low oxygen content. When Pt/Al-SBA-15 was used, compared to Al-SBA-15, the improvement of bio-oil quality was more profound; the yield of high-value-added aromatics increased, while the yields of acids and oxygenates decreased.

Synthesis of mesoporous SAPO-34 zeolite from mesoporous silica materials for methanol to light olefins

Mesoporous SAPO-34 zeolites were synthesized by using as-prepared mesoporous silica material as both silica source and mesopore tailor. The mesoporous SAPO-34 zeolite materials thus obtained are characterized by a series of different techniques, including poweder X-ray diffraction pattern, nitrogen physisorption analysis, scanning electron micrograph, temperature programmed desorption of ammonia, and inductively coupled plasma atomic emission spectrometry. The resultant mesoporous SAPO-34 crystals exhibit sphere-like particle with zeolite layer units. The mesopore size distribution and particle size can be changed by amounts of silica source and water. The methanol-to-olefins (MTO) reactions using these mesoporous SAPO-34 zeolites are carried out with a fixed-bed reactor. Catalytic tests exhibit that the mesoporous SAPO-34 zeolite materials show high catalytic activity compared with the conventional SAPO-34 for MTO reaction. The better catalytic activity and longer life time of the mesoporous SAPO-34 catalysts in MTO are mainly due to the existence of the mesoporosity of SAPO-34 with small particle size.

Structural influence of ordered mesoporous carbon supports for the hydrogenation of carbon monoxide to alcohols

A series of ordered mesoporous carbon materials (OMCs) possessing well-ordered nanoporosity with different mesopore structures were synthesized by the template-synthesis route. Two different pore strucutes (2-dimensional hexagonal and 3-dimensional cubic structures) and two different framework-configurations (rod-type and hollow-type carbon frameworks) are prepared by using the two different silica templates and synthetic conditions. The ordered mesoporous carbon supported promoted-rhodium catalysts were preparted by an incipient wetness method. The promoted Rh-OMC catalysts are tested by a fixed bed reactor for the catalytic conversion of syngas-to-alcohols. The characteristics of the promoted Rh-OMCs catalysts were scrutinized through a series of different techniques, including transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and N2 sorption analysis, and the catalytic performance was tested in a fixed-bed reactor. It was found that the promoted Rh-OMC catalysts exhibited the different catalytic activity and selectivity of alcohols, which could be attributed to the size of metal nanoparticles being confined by the different mesostructure of OMCs.

Effect of Pt particle size on the hydroisomerization of n-dodecane over Pt/Ai-SBA-15 catalysts

The hydroisomerization of n-dodecane was carried out over platinum-impregnated Al-SBA-15 as a bifunctional catalyst. A range of Pt/Al-SBA-15 catalysts with a Pt particle size of 1.7, 2.9 and 7.1 were prepared to examine the effect of the Pt particle size on the activity and selectivity for the hydroisomerization of n-dodecane. The catalysts were characterized by transmission electron microscopy, X-ray diffraction, nitrogen adsorption, pyridine Fourier transform infrared spectroscopy and NH3 temperature programmed desorption. The hydroisomerization of n-dodecane was performed in a batch-type reactor at 350 degrees C and 20 bar. The Pt(2.9)/Al-SBA-15 catalyst showed the highest selectivity to iso-dodecane due to its largest number of medium strength Brønsted acid sites and the optimum ratio of metallic/acid sites.

Effect of the preparation method of support on the aqueous phase reforming of ethylene glycol over 2 wt% Pt/Ce0.15Zr0.85O2 catalysts

The effect of catalyst support on the aqueous phase reforming of ethylene glycol over supported 2 wt% Pt/Ce0.15Zr0.85O2 catalysts have been investigated. Various types of Ce0.15Zr0.85O2 mixed oxides were prepared by hydrothermal precipitation (CZH), modified precipitation (CZM), co-precipitation (CZC), sol-gel (CZS) methods, respectively. Catalysts were characterized by XRD, N2 sorption analysis, and cyclohexane dehydration for relative metal dispersion. The support effect on the activity of 2 wt% Pt/Ce0.15Zr0.85O2 catalysts with different preparation method was given as follows: CZH < CZM < CZC < CZS. Pt/Ce0.15Zr0.85O2 (CZS) catalyst showed good catalytic activity for APR reaction due to its high metal dispersion and reducibility. The effect of reaction conditions such as reaction temperature, weight hourly space velocity (WHSV) was also studied. The hydrogen production rate and hydrogen yield increased in proportion to the reaction temperature and corresponding system pressure, whereas WHSV did not affect.

Catalytic pyrolysis of mandarin residue from the mandarin juice processing industry

In this study, the catalytic pyrolysis of mandarin residue from the mandarin juice processing industry was carried out using pyrolysis gas chromatography/mass spectroscopy and employing microporous zeolite catalysts, HZSM-5 (SiO2/Al2O3=23 and 80) and HBeta (SiO2/Al2O3=25). The effect of acidity of the catalyst was investigated by comparing the activity of two HZSM-5 catalysts with different SiO2/Al2O3 ratios. The effect of catalyst structure was explored by comparing the results obtained using HZSM-5 (23) and HBeta. Most oxygenates produced from non-catalytic pyrolysis were removed by catalytic upgrading, whereas the yields of mono-aromatics, which are important feedstock materials for the chemical industry, increased considerably, improving the quality of the bio-oil produced. HZSM-5 (23), having the highest acidity among the catalysts used in this study, showed superior catalytic activity to those of HZSM-5 (80) and HBeta. Pt/HZSM-5 (23) and Ga/HZSM-5 (23) resulted in an even higher yield of aromatics.

Synthesis of mesoporous SAPO-34 molecular sieves and their applications in dehydration of butanols and ethanol

Microporous SAPO-34 molecular sieves were hydrothermally synthesized with microwave irradiation in the presence of tetraethylammonium hydroxide (TEAOH) as a template. SAPO-34 molecular sieves with mesoporosity were also prepared in the presence of carbon black as a hard template. By increasing the content of the carbon black template in the synthesis, the mesopore volume increased. Dehydration of alcohols (butanols and ethanol) was carried out with the synthesized SAPO-34 molecular sieves, and the lifetime of the catalysts for the dehydration reaction increased as the mesoporosity increased. Moreover, the performance of the microporous catalyst synthesized with microwave was better than that of the catalyst obtained with conventional electric heating. The relative performance of the catalytic dehydration may be explained by the mesoporosity and the crystal size. Therefore, it may be concluded that small-sized SAPO-34 molecular sieves with high mesoporosity can be produced efficiently with microwave irradiation in the presence of carbon black template, and the molecular sieves are effective in the stable dehydration of alcohols.

Catalytic characteristics of titanium oxide/MCM-41 synthesized by liquid phase atomic layer deposition

Titanium oxide on MCM-41 was synthesized using the atomic layer deposition (ALD) method. BET, XRD, NH3-TPD and EDS were used to study the structural properties of the supported titanium oxides. The surface area of catalysts decreased with increasing of the amount of titanium in precursor solution. However, unique characteristics of 2-D hexagonal structure of mesopores in MCM-41 were maintained. The Ti/MCM-41 catalyst with titanium loading of 12.6 wt% showed the highest activity in the dehydration of 2-butanol, which was attributed to the highest overall amount of acid sites among the Ti/MCM-41 catalysts.

Hydroconversion of n-dodecane over nanoporous catalysts

Platinum catalysts impregnated on different nanoporous materials, Meso-MFI, Si-SBA-15 and AI-SBA-15, were synthesized, and the hydroconversion of n-dodecane over these catalysts was performed. The catalytic characteristics were analyzed by Brunauer-Emmett-Teller surface area, X-ray diffraction, N2-adsorption-desorption and temperature programmed desorption of NH3. The effects of operation parameters, such as temperature and pressure, on the catalytic activities were investigated. The catalytic activities were affected considerably by the acidic properties of the catalysts, temperature and pressure. Higher acidity, high temperature and low hydrogen pressure resulted in higher hydroconversion and facilitated hydrocracking. The weak acidity, low temperature and high hydrogen pressure resulted in lower hydroconversion and higher selectivity to i-dodecane.

Catalytic conversion of waste particle board to bio-oil using nanoporous catalyst

The catalytic pyrolysis of waste wood including the particle board was examined by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to produce bio-oil. Three different catalysts with a nanoporous structure, Al-MCM-48, Meso-MFI, and Pt-Meso-MFI, were used and their performances were compared. When MCM-48 was used, the quality of the bio-oil product was better than that prepared by non-catalytic pyrolysis but the improvement was limited due to its weak acid sites. On the other hand, Meso-MFI, which has both an MFI structure and strong acid sites, exhibited much better cracking ability and higher selectivity for aromatics. Moreover, Pt-impregnation on Meso-MFI resulted in an even higher selectivity for aromatics and phenolics, which are important raw materials in various petroleum chemical processes.

KEYWORDS

Catalytic Pyrolysis, Py-GC/MS, Waste Particle Board, AI-MCM-48, Meso-MFI,

Production of biohydrogen by aqueous phase reforming of polyols over platinum catalysts supported on three-dimensionally bimodal mesoporous carbon

Now in 3D! Three-dimensionally bimodal carbons (3D-BMC) with mesopores of tunable size (controlled through the polymerization of the carbon precursor) are synthesized. After loading with platinum, the catalysts are used in aqueous phase reforming of polyols, and show superior performance in terms of carbon conversion, hydrogen yield, selectivity, and hydrogen production rate compared to platinum catalysts supported on activated carbon or two-dimensional CMK-3.

Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS

The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI) and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity.

Utilization of a by-product produced from oxidative desulfurization process over Cs-mesoporous silica catalysts

We investigated the use of Cs-mesoporous silica catalysts to upgrade a by-product of oxidative desulfurization (ODS). Cs-mesoporous silica catalysts were characterized through N2 adsorption, XRD, CO2-temperature-programmed desorption, and XRF. Cs-mesoporous silica prepared by the direct incorporation method showed higher catalytic performance than a Cs/MCM-41 catalyst by impregnation method for the catalytic decomposition of sulfone compounds produced from ODS process.

Catalytic upgrading of oil fractions separated from food waste leachate

In this work, catalytic cracking of biomass waste oil fractions separated from food waste leachate was performed using microporous catalysts, such as HY, HZSM-5 and mesoporous Al-MCM-48. The experiments were carried out using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to allow the direct analysis of the pyrolytic products. Most acidic components, especially oleic acid, contained in the food waste oil fractions were converted to valuable products, such as oxygenates, hydrocarbons and aromatics. High yields of hydrocarbons within the gasoline-range were obtained when microporous catalysts were used; whereas, the use of Al-MCM-48, which exhibits relatively weak acidity, resulted in high yields of oxygenated and diesel-range hydrocarbons. The HZSM-5 catalyst produced a higher amount of valuable mono aromatics due to its strong acidity and shape selectivity. Especially, the addition of gallium (Ga) to HZSM-5 significantly increased the aromatics content.

Catalytic pyrolysis of oilsand bitumen over nanoporous catalysts

The catalytic cracking of oilsand bitumen was performed over nanoporous materials at atmospheric conditions. The yield of gas increased with application of nanoporous catalysts, with the catalytic conversion to gas highest for Meso-MFI. The cracking activity seemed to correlate with pore size rather than weak acidity or surface area.

Catalytic conversion of 1,2-dichlorobenzene over mesoporous materials from zeolite

In this study, 1,2-dichlorobenzene (DCB), an important precursor of PCDDs and PCDFs, was chosen as a suitable model compound for the catalyzed deep oxidation of dioxin. The recently developed mesoporous materials from zeolites (MMZ) were used for the first time as a support for an oxidation catalyst. The catalytic oxidation of 1,2-dichlorobenzene over Pt/MMZ was carried out, and the catalytic activity was compared with that of Pt/gamma-Al2O3, Pt/Al-MCM-41 and Pt/Beta catalysts. Pt/MMZ showed the highest catalytic activity among the catalysts tested. Interestingly, the catalytic activity of Pt/MMZ was maintained (> 40%) at low temperatures (250 degrees C) at which the other catalysts showed extremely low activity (< 5%). The high catalytic activity of Pt/MMZ was attributed to both the sufficient acidity and mesoporosity of the MMZ support.

Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound

Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated.

Catalytic removal of sulfur dioxide from dibenzothiophene sulfone over Mg-Al mixed oxides supported on mesoporous silica

Dibenzothiophene sulfone (DBTS), one of the products of the oxidative desulfurization of heavy oil, can be removed through extraction as well as by an adsorption process. It is necessary to utilize DBTS in conjunction with catalytic cracking. An object of the present study is to provide an Mg-Al-mesoporous silica catalyst for the removal of sulfur dioxide from DBTS. The characteristics of the Mg-Al-mesoporous silica catalyst were investigated through N2 adsorption, XRD, ICP, and XRF. An Mg-Al-mesoporous silica catalyst formulated in a direct incorporation method showed higher catalytic performance compared to pure MgO during the catalytic removal of sulfur dioxide from DBTS. The higher dispersion of Mg as well as the large surface area of the Mg-Al-mesoporous silica catalyst strongly influenced the catalyst basicity in DBTS cracking.

Physicochemical characteristics of SAPO-34 molecular sieves synthesized with mixed templates as MTO catalysts

In the present work, a variety of SAPO-34 catalysts have been prepared using various templates such as a single or mixtures of tetraethylammonium hydroxide (TEAOH), morpholine, diethylamine (DEA), triethylamine (TEA), dipropylamine (DPA), isopropylamine (IPA) and Diethanolamine (DEtA). It is shown that crystal morphology and physicochemical properties were affected by the kinds of templates and mixture contents. Especially, inexpensive SAPO-34 catalyst with good crystal properties and catalytic performance was obtained by using mixed template of DEA and TEAOH. Through N2 isotherm, XRD, SEM, NH3 TPD and 29Si-NMR techniques, the effect of mixed template on the crystal morphology, acidity and Si distribution were investigated. Catalytic activity and life stability of SAPO-34 in MTO reaction was improved by using mixed template because of the distinction of the crystal size, acidity and Si distribution.