Catalysts for production of lubricant base oil from α-olefins, i. e., Friedel Crafts, Ziegler-Natta and metallocene catalysts, were reviewed, including the catalytic systems and their composition，research methods and the catalytic properties.

YAO Sanli;CHEN Jianlin;GAO Qiangli

Ultramicro ZSM5 zeolites were synthesized using Na2SiO3·9H2O, Al2(SO4)3·18H2O and template agents with different ratio and at normal temperature and pressure. The samples were characterized by Benzene Adsorption, XRD, SEM and IR. The results showed that the samples synthesized had typical crystal structure of ZSM5 zeolite with ultramicro grain size.

Deactivated FDO catalyst for desulfurization and olefin-reducing of FCC gasoline was regenerated by coke burning-out and modified by nickel via impregnation, and then characterized by XRD, XRF, IR and NH₃-TPD. Catalytic behaviors of the catalysts were tested in a small fixed-bed reactor under 370 ℃, 3.0MPa,WHSV 3.0h^-1 and H₂/oil 600. The results showed that coke burning-out from deactivated FDO catalyst completely restore the activity for converting olefins to aromatics, while the desulfurization activity declined notably. By impregnating proper amount of nickel sulfate onto the regenerated FDO catalyst, both the activity for converting olefins to aromatics and that for desulfurization were restored satisfactorily.

In-situ crystallization is a way for utilization of chemically-active SiO₂ and Al₂O₃ in Kaolin as the source for synthesis of NaY zeolite. The transfer of species in the in-situ crystallization was investigated via base extraction of Kaolin constituents. The results showed that in the initial stage, active silica and alumina in the solid phase rapidly transferred to the liquid while sodium oxide transferred to the solid; silicon, aluminum and sodium in the liquid decreased with crystallization time.

Influence of zeolite shearing, chloride and ammonium ions on the ion exchange of zeolites for reducing ammoania-nitrogen pollution was investigated using chemical, analysis XRD and small fixed fluidized bed reactor. The results indicated that M ions exchanged the sodium in the zeolite more easily than ammonium ions; M was less likely to impair crystallinity of the zeolite under high-temperature hydrothermal condition; grain size of the zeolite had little influence on sodium oxide content after ion-exchange; introduction of M salt resulted in low-sodium zeolite with comparable crystallinity and cell parameters to conventional procedure, with reduction of ammonium quantity by 50% and without increase in preparation cost. The catalytic cracking activity of the catalyst using zeolite prepared by this technique as the active constituent was comparable to those by conventional techniques.

Nickel was loaded over H-ZSM-5 and H-MOR and performance of the resultant catalysts for hydrodealkylation was investigated using isopropylbenzene(IPB) as the model compound. Influence of zeolite proportion, metal content and acid content on the catalytic activity was investigated. The results showed that IPB conversion, benzene, toluene and xylene (BTX) yield were remarkably enhanced over Ni/(H-ZSM-5+H-MOR) catalyst treated by acid. IPB conversion of 81.5%, BTX yield of 72.8% and selectivity to BTX of 89.2% were attained under the following condition: 340 ℃, 0.8 MPa, LHSV 1 h^-1.

Kinetics for esterification of waste cooking oil with methanol in the presence of methanesulfonic acid catalyst was studied. Methanol was continuously pumped into waste cooking oil and water and unreacted methanol were distilled simultaneously. The results showed that the reaction was of first-order with activation energy of 76.06 kJ·mol^-1. The reaction rate increased with increasing catalyst dosage, methanol flow rate and reaction temperature.

RuO₂/ZSM-5 prepared by in-situ reaction was characterized by XRD, XPS and TEM. The results indicated that there existed mainly RuO₂ particles of about 20 nm dispersing in the carrier; introduction of ruthenium species did not change structure of ZSM-5 carrier; most ruthenium existed in Ru(Ⅳ) . RuO₂/ZSM-5 were used as the catalyst for partial oxidation of alcohols in air atmosphere. The results showed that RuO₂/ZSM-5 could not only catalyze partial oxidation of aromatic alcohols and allyl alcohols (active alcohols), but also catalyze that of inactive alcohols.

The influence of promoters on the activity of activated carbon supported cobalt catalysts for ammonia synthesis was studied. The results showed that the presence of promoters such as Ba, K and Sm led to enhanced ammonia synthesis activity; Ba was the best promoters for Co/AC catalyst, with the optimal activity at Ba/Co molar ratio of 0.3. Addition of Sm led to decline activity of Ba-Co/AC catalyst, while a little content of potassium (K/Co molar ratio of 0.25-0.5) improved activity of Ba-Co/AC catalyst. Ammonia synthesis activity of over 120 mmol·(g·h)^-1 was obtained over Ba-K-Co/AC catalyst under 10 MPa, 10 000 h^-1 and 450 ℃.

Supported CuO/ZrO₂ catalysts were prepared by impregnation method. Doped CuO-ZrO₂ catalysts were prepared using Zr(OH)₄ gel as the precursor. CuO·ZrO₂ catalysts were prepared by co-precipitated method. The as-prepared catalysts were characterized by XRD, N₂ adsorption-desorption, TEM and SEM. Catalytic activity of the catalysts was investigated using dehydrogenation of ethanol to ethyl acetate as the probe reaction. The results indicated that all the catalysts were of nanometer size particles and exhibited catalytic activity for dehydrogenation of ethanol to ethyl acetate. The CuO·ZrO₂ catalyst prepared by co-precipitation had the highest catalytic activity, with ethanol conversion of 49% and selectivity to ethyl acetate of 88% at reaction temperature of 473 K.

ZSM-22 zeolite catalysts modified with different contents of SiO₂ or La₂O₃ were prepared by impregnation method. Methylation of toluene with methanol to p-xylene was carried out over these catalysts by means of a fix-bed flow reactor. The results showed that selectivity to p-xylene was higher than m- and o- isomers over ZSM-22 catalysts. The modified catalysts exhibited higher selectivity to p-xylene but lower toluene conversion than ZSM-22.Toluene conversion declined while selectivity to p-xylene increased with SiO₂ or La₂O₃ content.ZSM-22 catalysts modified by La₂O₃ had the most remarkable increase in selectivity. Toluene conversion over ZSM-22 modified by La2O3 and SiO₂ combined was higher than over those modified solely by La₂O₃ , while selectivity to p-xylene was comparable in both case, with slight increase in selectivity to xylene.

Four intermediate products, 9,9-bis-(hydromethyl)fluorene, 9,9-bis(methomethyl) fluorene, monoethyl succinate and monoethyl succinyl chloride, were synthesized via etherification, esterification and Friedel-Crafts acylation, using fluorene as the starting material. 2-monoethyl succinyl-9,9-bis(methoxymethyl)fluorene was finally synthesized as the end product. The intermediate products and end product were characterized by 1H-NMR and 13C-NMR. A novel propylene polymerization catalyst was synthesized using 2-monoethyl succinyl-9,9- bis(methoxymethyl) fluorene as the internal electron donor and the performance of the catalyst was tested for propylene bulk polymerization.

2,6-amino-3,5-nitropyrazine(ANPZ) was synthesized from 2,6-dichloropyrazine via nucleophilic substitution，nitrification and treatment by ammonia, and then reacted with sodium hypochlorite to form 4-amino-5-nitro-1,2-furazanopyrazine(ANFP), with ANFP yield of 30%. The intermediate and end products were characterized by IR, thin-layer chromatography and melting point measurement.

Titania thin film doped with W⁶⁺ and supported on titanium surface were prepared by sol-gel method. The results indicated that optimum photocatalytic activity of the TiO₂ thin film was attained under calcination temperature of 520 ℃; doping of W enhanced photocatalytic activity of the TiO₂ thin film. Optimal photocatalytic activity of the TiO₂ thin film doped with W6+ was obtained at W⁶⁺ concentration of 6.04×10¹⁶ atoms·cm^-3. XRD results showed that both pure and ion-doped TiO₂ thin films were of anatase type, with no tungsten oxides detected.

Using commercial NaBiO₃·nH₂O as photocatalyst, the effects of drying temperature on its structure and photocatalytic activity were investigated. Photocatalytic behaviors and reusability of sodium bismuthate in photocatalytic degradation of different organic pollutants were investigated. The results showed that methyl orange, orangeⅡ, methylene blue and phenol were degraded effectively by NaBiO₃ under visible light irradiation, and the photocatalytic activity was enhanced at appropriate drying temperature. Commercial NaBiO₃·nH₂O can be used as a recyclable photocatalyst for degradation of pollutants.

FP-DS sulfur transfer catalyst was prepared by sol method. Effects of structure of solid solution spinels, calcination temperature, hydrothermal aging and introduction of transition metals on the sulfur transfer catalyst and the ways for lowering abrasion loss were investigated. The results showed that FP-DS sulfur transfer catalyst could effectively reduce the content of SO₂ in the flue gas from regeneration, with SO₂ adsorption efficiency of over 60%, desorption percentage of up to 100% and abrasion loss of less than 3.5%·h^-1. Use of the sulfur transfer catalyst had no obvious effect on FCC product distribution and quality.

The properties of and latest studies on initiating agents for NaY zeolites, including conventional sol initiating agents, high-temperature long-effect sol initiating agents, high-alumina sol initiating agents, modified sol initiating agents and gel initiating agents, were reviewed. The means for characterization of the initiating agents, e.g., spectrophotometer, UV Raman, liquid phase ^29Si-NMR, liquid phase ²⁷Al-NMR, solid phase ²³Na-NMR, electron diffraction and silicon-molybdenum kinetics, were compared.

Latest researches in mercaptan conversion catalysts and mechanisms for mercaptan oxidation were reviewed, including cobalt phthalocyanine and solid base catalysts, as well as base-catalyzed mercaptan oxidation reaction mechanism and redox catalytic mercaptan oxidation mechanism. It was pointed out that substitution of cobalt phthalocyanine by novel mercaptan conversion catalysts would be the trends in this aspect.

The processes and catalysts for production of dimethyl ether(DME) and their commercialization were reviewed, including two-step(liquid phase dehydration, gaseous phase dehydration, cation liquid catalytic reaction, catalytic distillation) and one-step(three-phase slurry bed, slurry-fixed-bed series and fixed bed) processes, related catalysts and their features.

Synthesis of CeO₂ with controllable morphology has attracted much attention and become an important part of rareearth researches. In this paper, CeO2with novel navicular morphology was synthesized via simple hydrothermal treatment, using lysozyme as the template, cerous nitrate as the cerium source and potassium carbonate as the precipitant, and characterized by XRD, SEM, TEM and N₂-adsorption. The results showed that the navicular CeO2had an elliptical structure, with the overall three-dimensional structure assembled by many CeO₂ crystals with grain size of (8-10) nm and surface area of 32.2 m²·g^-1. Activity of the navicular CeO₂ was investigated using CO catalytic oxidation as the probe reaction, with ignition temperature T₅₀  of 230 ℃ and complete conversion temperature T₁₀₀ of 250 ℃.

Hydrogen peroxide was synthesized from H₂ and O₂ at room temperature and atmospheric pressure over Pd/TiO₂ catalyst prepared by impregnation-precipitation. The effects of pH value, stirring time t1, static time t₂ and calcination temperature on activity of the catalyst were investigated via orthogonal experiment with influential order as follows: pH value＞stirring time t₁＞calcination temperature＞static time t₂. Catalyst with the optimum activity was prepared under the condition of pH=8，t₁=0，t₂=0 and calcination at (250-300) ℃ for 3 hours.

A NaY zeolite with multi-dimensional surface (DNY) was synthesized using function-gradient design concept and properties of the zeolite and the zeolite-based catalysts were characterized by XRD, XRF, BET, MAT and ACE. The results showed that hydrothermal stability of the rare-earth Y zeolite REY-D prepared from the as-synthesized NaY zeolite was inferior to that of REY-C zeolite prepared from conventional NaY zeolite, while reversed results were observed after combining the REY zeolite with matrix, and these tendency became more and more remarkable with aging time. ACE test results showed that catalysts prepared from the as-synthesized NaY zeolite exhibited higher selectivity to gasoline and lower selectivity to heavier and diesel oil, with low content of olefins in gasoline and higher content of olefins in LPG.

The process，principle and application of rotary flash dryer in zeolites production were reviewed. Compared with conventional blade dryer, rotary flash dryer features simpler operation, lower material consumption, higher yield and better product quality, with increased catalyst productivity(14.5 t·d^-1 to 17.5 t·d^-1)，decreased energy consumption (0.9 t·t^-1 to 0.774 t·t^-1)，lower fuel gas consumption(0.126 t·t^-1) and lower dust in emission stream(＜90 mg·m^-3)。

HY-, Hβ- and HZSM-5-supported phosphotungstic heteropolyacid(HPWA) catalysts were prepared by ball grinding-mixing method. Behaviors of the HPWA, HY, Hβ, HZSM-5, HPWA/HY, HPWA/Hβ and HPWA/HZSM-5 catalysts were investigated for etherification of light gasoline and methanol. Reaction results in an autogenous pressure kettle showed that HPWA/Hβ with 40% HPWA exhibited satisfactory activity, with optimum reaction condition as follows: m(catalyst)∶m(gasoline)=1∶12, reaction temperature 90 ℃, m(methanol)∶m(gasoline)=1∶3, water content in methanol=4%, reaction for 2 h. Olefins conversion of 55.78%, selectivity to ether of 64.00% and ether yield of 35.69% were obtained under the optimal condition.

Biodiese were synthesized via transesterification of soybean oil with ethanol in the presence of solid acids as the heterogeneous catalyst. Silica-supported methanesulfonic acid(CH₃SO₃H-SiO₂) was prepared by sol-gel method as the catalyst. Effects of treatment temperature for the catalyst, n(ethanol)∶n(soybean oil), dosage of the catalyst, dosage of heptane and reaction time were investigated. The results showed that the silica-supported methanesulfonic acid (CH₃SO₃H-SiO₂)catalysts exhibited high activity for the transesterification. Biodiesel yield of 98.33% was obtained under optimum condition as follows: catalyst being treated at 130 ℃, n(ethanol)∶n(soybean oil)=6∶1, mass fraction of the catalyst in soybean oil=5.0%, mass fraction of heptane in soybean oil=30.0%, reflux time 6 h. The solid acid catalysts have better adaptability to the feeds than solid base catalysts.

Catalytic activity of porous dolomite pellets for decomposition tar from biomass gasification was enhanced via introducing nickel (Ni). Ni/dolomite powder was prepared via coordinated precipitation method and then formed to porous Ni/dolomite pellets. Steam reforming of benzene (as the model compound for tar) was carried out over porous Ni/dolomite pellets in a fixed bed reactor. Effects of calcination temperature and nickel oxide content on catalytic activity of the porous Ni/dolomite pellets were investigated. Maximum gas yield of 83.0% was obtained over porous Ni/dolomite pellets prepared under calcination temperature of 750 ℃ and with nickel oxide content of 13.5%(mass fraction). Coke formation rate was almost constant at 4.5% when the catalyst was prepared under calcination temperature of （450-900） ℃ and with nickel oxide content of 0-22.5%. The coked porous Ni/dolomite pellets were regenerable by calcination at 900 ℃ for 2 h, with catalytic activity similar to that of fresh pellets.

Synthesis of isoamyl propionate catalyzed by acidic ionic liquids was investigated, including the influence of different ionic liquids, reaction temperature, reaction time and dosage of ionic liquid (reactant-to-IL mole ratio). Isoamyl alcohol conversion of 99.43% and selectivity to isoamyl propionate of 100% were obtained under optimum reaction condition as follows: ［(CH₂)₄SO₃HMIm］HSO₄ as the catalyst, n（propanoic acid)∶n（isoamyl alcohol)∶n（IL)=5∶5∶1, 60 ℃, reaction for 2 h. The ionic liquid was repeatedly used for five cycles without apparent loss of catalytic activity.

H₃PW₁₂O₄₀/TiO₂ catalyst was prepared by sol-gel method and characterized by FT-IR. The H₃PW₁₂O₄₀/TiO₂ was used as the catalyst for synthesis of n-butyl p-hydroxybenzoate from n-hydroxy benzoic acid and n-butyl alcohol. The effects of reactants proportion, catalyst dosage, reaction time and repeated use of the catalyst were investigated and the favorable reaction condition was obtained as follows: p-hydroxy benzoic acid 0.1 mol,n(p-hydroxy benzoic acid)∶n(n-butyl alcohol)=1.0∶5.0,dosage of the catalyst 1.2 g, reaction time 4.0 h. n-Butyl p-hydroxybenzoate yield of over 85% was attained under the above-mentioned reaction condition.

Removal of toluene, a typical volatile organic compounds(VOCs) by low-temperature plasma catalytic technique was studied. Carbon powder, phenolic resins, organic polymers and organic solvent were mixed as the precursor and a metal foam based carbon composite material was prepared via carbonization, steam activation and loading manganese catalyst. The composite material was characterized by scanning electron microscope(SEM), X-ray diffraction(XRD) and automatic surface area and micropore porosity analyzer. For degradation of toluene directly by dielectric barrier discharge plasma without presence of carbon composite material, the removal efficiency increased with increasing input voltage. Two-stage dielectric barrier discharge plasma reactor with carbon composite material was used for removal of toluene.Toluene was partially decomposed by high-energy particles generated in the dielectric barrier discharger in the first stage, and further degraded by combination of the long-life active species generated by the dielectric barrier discharge, ozone and mental foam carbon composite material. Toluene removal efficiency of 99.4% and selectivity to carbon dioxide of 72.2% were attained under input voltage of 10 kV, with effectively-controlled formation of ozone by-product.

Zn/TiO₂ catalysts with different amount of Zn were prepared by precipitation method and used in photocatalytic degradation of methyl orange. Structure of the Zn/TiO₂ catalysts was characterized by UV-DRS and XRD. The results showed that amount of doping Zn had much influence on degradation of methyl orange, with optimum Zn content of 1.5%(molar fraction) in Zn/TiO₂. The changes of DRS differential coefficient peak values of catalysts were consistent with the changes of their photocatalytic activity, with the maximum differential coefficient peak value occurring at 1.5%(molar fraction) Zn in Zn/TiO₂. XRD results showed that Zn was highly dispersed in the lattice of TiO₂. For 1.5%Zn/TiO₂ with catalyst dosage of 2 g·L^-1, optimal degradation condition were obtained as follows: initial pH=3, initial methyl orange concentration 15 mg·L^-1. Methyl orange degradation rate of 98.6% was obtained under the optimal condition.

Using AgCl nanoparticles as the crystal seeds and in the presence of trisodium citrate, Ag/AgCl coreshell composite nanoparticles were synthesized by photochemical reduction method and their photocatalytic properties were investigated using methylene blue degradation as the model reaction. The results showed that the Ag/AgCl nanoparticles exhibited surface plasma resonance effect, effectively enhancing absorption of visible light and the photocatalytic activity. methylene blue degradation rate of 95% and COD removal rate of 92% were obtained under the following condition: catalyst dosage 10 mg·L^-1, methylene blue concentration 10 mg·L^-1, visible light irradiation for 60 min.

catalytic chemistry; Ag/AgCl

Methyl orange solution was degraded over niobic acid under highpressure mercury lamp irradiation. Effects of dosage of H₂O₂ and catalyst and initial concentration of methyl orange on the degradation were investigated. Methyl orange decolorizing rate of 97％ was obtained under the optimal condition as follows: initial concentration of methyl orange 15 mg·L^-1, dosage of H₂O₂ 5.0 mL·L^-1,dosage of the catalyst 1.5 g·L^-1, illumination time 1 h. Mechanism of the photocatalytic degradation of methyl orange follows the firstorder kinetic equation in lower initial concentration range

Pt-Sn/Al₂O₃ catalysts with different loadings of Sn were prepared by sol-gel and impregnation method and characterized by TEM, H₂-adsorption and XPS. Properties of the catalysts for dehydrogenation of propane were investigated under severe condition, i.e., high temperature (550 ℃) and in the absence of H₂. It was found that sol-gel method led to encapsulation of Sn in the support structure and avoided precipitation during reduction and thus enhanced the catalytic activity. Propylene yield of 36.3% and selectivity to propylene of 98.8% were obtained over the catalyst under 550 ℃ and 6.5 h.

MgO/C-CoPcS catalysts were prepared by impregnation method and characterized by XRD, BET, DTA-TG and FTIR. Effects of Mg/C mole ratio, drying temperature and impregnating solvent on their catalytic activity were investigated. The results indicated that during the initial reaction period, activity of the catalyst was determined both by amount of base and surface area; then with proceeding of the reaction, the activity was mainly determined by amount of base. Optimal activity of the catalyst was attained underMg/C mole ratio of 0.2, drying temperature of 200 ℃and impregnation in methanol.

SBA-15 mesoporous molecular sieves were prepared at different crystallization temperature using polyglycol-polypropanetriol-polyglycol (P123) as the template and tetraethyl orthosilicate as the silica source. Adsorption-desorption behaviors of the SBA-15 molecular sieves for toluene and ethyl acetate were investigated by breakthrough curves and TPD techniques. The experimental results showed that the adsorption capacity declined while desorption temperature went down when crystallization temperature went up from 80 ℃ to 135 ℃. Adsorption capacity of the SBA-15 for ethyl acetate was much higher than that for toluene, indicating that the SBA-15 materials were philic to ethyl acetate but phobic to toluene.

Molybdenum carbide (Mo₂C) catalysts were prepared via temperature programmed carbonization of molybdenum trioxide with CH₄/H₂ and characterized by XRD and BET. Hydrodenitrogenation (HDN) behaviors of the Mo₂C catalysts was investigated in a high-pressure micro-reactor, using 1 000 ng·μL^-1 quinoline/cyclohexane as the model reactants. β-Mo₂C with high purity was prepared under the following favorable condition: carbonization at 675 ℃ for 150 min. Further increase in carbonization temperature resulted in declining BET surface area and increasing coke formation on the surface, and hence declining HDN activity of Mo₂C. The high-pressure microreactor experimental results indicated that Mo₂C exhibited remarkably higher activity than MoS₂ and MoO₃ under 3.0 MPa, 8 h^-1, V(H₂)∶V(reactants) of 500∶1 and N content of 1 000 ng·μL^-1 in quinoline/cyclohexane solution, with quinoline HDN conversion of 58.69% under 360 ℃.

Preparation of C2 front-end hydrogenation catalyst was studied using equality design method and optimal constitution and preparation process for the catalyst were determined. The 1 000 hours test run of the as-prepared catalyst showed activity of the catalyst was slight lower than that of the reference catalyst while its selectivity was higher. H₂-O₂ titration results indicated that catalyst prepared by the process developed by equality design method resulted in better dispersion and hence higher activity and selectivity.

A honeycomb dioxins decomposition catalyst was prepared by extrusion molding, using titania as the carrier and V₂O₅ and WO₃ as the active components, with axial crush strength of over 100 N·cm^-2, attrition loss of less than 3%, pitch line of （4-7） mm, wall thickness of （1.0-1.2） mm, shrinking percentage of less than 2%, bulk density of （0.5-0.7） g·cm^-3, geometric surface area of over 500 m²·m^-3 and catalytic activity of over 90%. The honeycomb catalyst, when used in catalytic decomposition of dioxins in the flue gas from municipal solid waste incineration, features low pressure loss, high catalytic activity and long service life.

γ-Al₂O₃-support Cu-Zn oxide catalysts were prepared by coimpregnation method with CuO-ZnO loadings of 35%(mass fraction) and characterized by XRD，BET and H₂-TPR. Effects of different promoters (Co, Ni, Mg, Fe, Mn, Ba, Ce）were investigated. Activity of the catalysts for N₂O decomposition were tested in a microreactor. The results showed that the Cu-Zn oxide catalysts had the similar Co₃O₄ spinel structure as CuxZn_1-xAl₂O₄, with increased BET surface area due to addition of metal promoters. Activity of the catalysts for N₂O catalytic decomposition had relations not only to reduction temperature of Cu³⁺ to Cu²⁺, but also to the crystal grain size and BET surface area. Catalysts with 3% nickel promoter exhibited the highest N₂Odecomposition activity, with complete conversion of N₂O at 567 ℃. The N₂O catalytic decomposition activity was enhancd by adding metal promoters, except barium.