EFFECT OF CATALYST PRETREATMENT ON THE OXIDATION OF CARBON MONOXIDE OVER Au／NiO CATALYST

ＥＦＦＥＣＴＯＦＣＡＴＡＬＹＳＴＰＲＥＴＲＥＡＴＭＥＮＴＯＮＴＨＥＯＸＩＤＡＴＩＯＮＯＦＣＡＲＢＯＮＭＯＮＯＸＩＤＥＯＶＥＲＡｕ／ＮｉＯＣＡＴＡＬＹＳＴＥＦＦＥＣＴＯＦＣＡＴＡＬＹＳＴＰＲＥＴＲＥＡＴＭＥＮＴＯＮＴＨＥＯＸＩＤＡＴＩＯＮＯＦＣＡＲＢＯ...     

EFFECT OF Y_2O_3 ON THE PROPERTY OF NiO/Al_2O_3 CATALYST FOR PARTIAL OXIDATION OF METHANE

The effects of Y_2O_3 on the property of NiO/Al_2O_3 catalyst forcatalytic partial oxidation of methane were investigated in a continuous flowfixed bed reactor(20 mm i.d.,860 mm long).The catalysts werecharacterized by XRD and pore measurement.For comparison,similar studieswere carried out for the catalysts loaded with Zr or W oxide.The results showthat different additives and impregnating methods could greatly affect thedispersion of component Ni.The catalytic activity,the selectivity to CO andthe stability are improved because of the less facile interation between thesupport and nickel oxide,greater surface area and better dispersion of metalNi for NiO/Al_2O_3 catalyst modified by Y_2O_3.     

EFFECTS OF ALKALI AND RARE EATTH METAL OXIDES ON THE THERMAL STABILITY AND THE CARBON DEPOSITION OVER A NiO/Al_2O_3 CATALYST

采用固定床流动反应装置、ＣＯ吸附、ＴＧ、ＴＰＯ、ＸＰＳ和ＸＲＤ等手段考察了ＮｉＯ／Ａｌ２Ｏ３和ＬｉＮｉＬａＯ／Ａｌ２Ｏ３催化剂上的甲烷部分氧化反应。实验结果表明，ＬｉＮｉＬａＯ／Ａｌ２Ｏ３对甲烷部分氧化反应具有较高的反应活性。锂和镧的添加不仅改善了活性组分镍的分散度，而且提高了ＮｉＯ／Ａｌ２Ｏ３的抗积碳能力和热稳定性     

THE STUDY OF THE NON-STEADY KINETICS OF THE OXYDEHYDROGENATION OF ETHANE TO ETHYLENE OVER THE CATALYST OF Mo-V-Nb/Al_2O_3 BY THE TECHNIQUE OF TEMPERATURE PROGRAMMED TRANSIENT RESPONSE AND ELECTRIC CONDUCTIVITY

In this paper, instead of with the more expensive Fourier Transform Infrared Spectrometer(FTIR) a new technique of Temperature Programmed Transient Response(TP-TR) has been used with gas chromatography. Therefore, the TP-TR will be applied more widespreadly than ever before. With the technique of TP-TR and electric conductivity, the study is on the reaction mechanism and the adsorption behavior of the reactants and products to the present catalyst Mo-V-Nb/Al_2O_3 in the reaction from ethane through oxydehydrogenation to ethylene as the product. By Range-Kutta-Gill and Margarat methods, the kinetic parameters of the reaction elementary steps (i.e. rate constants, active energies and frequency factors) have been evaluated. The mathematical treatment coincides with the experimental results.     

SELECTIVE OXIDATION OF PROPANE OVER α-Bi_2Mo_3O_(12)/MoO_3 CATALYST

A series of highly dispersed bismuth molybdate series catulyst,Bi_xpMo_(12)O_y(x=1～8,y=40～61),were prepared from12-molybdophospho-ric acid under acidic condition.By means of IR and XRD,we found that thebasic composition of the catalysts wasα-Bi_2Mo_3O_(12)/MoO_,and the activity foroxidationof propane was ascribed to the co-effect ofα-Bi_2Mo_3O_(12)andMoO_3 probably.     

TPR AND CTPR STUDIES ON Ni/Al_2O_3 CATALYST FOR CATALYTIC PARTIAL OXIDATION OF METHANE TO SYNGAS

lntroductionTheconversi0nofnaturalgast0syngasviQtheCatalyticPartialOxidaion(CPO)ofCH4(Eq.l)lledlethibitsthepotentiaIt0replaceconventionalsteamreforming(Eq.2),withasubstalialreductioninplantsizc.Thisproccssisnotcncrg}intensivc.andalso}'ieldss}.nthesisgasx`.ithH2/COmolarratioof2.O.x`hichissuitabIcforman}'chcmicalproccsscs-suchasthcproductionofmethanoIovcrCu/Zn0catal}'st(Eq.3)andFischcr-Tropschs}nthcsisovcrCo'CucataI}'sts(Eq.4).CO 2H2-CH30H(3)nCO 2nH2-C,,H(2,, l) nH2O(4)Atprcscnt-…     

PARTIAL OXIDATION OF METHANE OVER NiO/Al_2O_3 MODIFIED BY METAL OXIDES

ＰＡＲＴＩＡＬＯＸＩＤＡＴＩＯＮＯＦＭＥＴＨＡＮＥＯＶＥＲＮｉＯ／Ａｌ２Ｏ３ＭＯＤＩＦＩＥＤＢＹＭＥＴＡＬＯＸＩＤＥＳ＊ＭｉａｏＱｉｎｇ，ＸｉｏｎｇＧｕｏｘｉｎｇ＊＊，ＸｕＬｉｎｇ，ＳｈｅｎｇＳｈｉｓｈａｎ，ＧｕｏＸｉｅｘｉａｎ（ＳｔａｔｅＫｅｙＬａ...     

KINETIC STUDY OF THE OXIDATIVE COUPLING OF METHANE OVER La_2O_3/BaSO_4 CATALYST

IntroductionOxidativccouplingofmethanc(0CM)hasbccnthcsubjcctofmuchintcrcstrcccntl}Man}'mctaloxides,alkali-mctaI-promotcdmctaloxidcs-mixcdmcta1oxidcsandchlorinc-prom0tedmCtuloxidcshavcbecnf0undtobcactivcfor0CMHot` cvcr.thcrcisatprcscntnoclearagreemcntaboutthcmcchanismofthecouplingrcaction.T\`omodclsll1.thcthdeal-rcdoxandthcLangmuir-Hinshtt-oodmcchanisms.havcbccndcvcIopcdtodcscr1bc0CMreation-thecsscntialdiffercnccbctt"ccnthctt"omodclsisthatthclattcrinvolvcsadsorbedmothancasarcactionintcrmcd…     

THE EFFECT OF ADDITIVE La_2O_3 ON THE DISPERSION AND THERMOSTABILITY OF NICKEL IN METHANATION CATALYST

It is showed that La_2O_3 and NiO could disperse on γ-Al_2O_3 as a monolayer and theirutmost monolayer capacities determined by quantitative XRD are 0.28g/100m~2 and 0.09g/100m~2respectively. In the methanation catalyst, Ni/La_2O_3/γ-Al_2O_3, the La_2O_3 is dispersed on thesurface of γ-Al_2O_3 as a monolayer and the metallic nickel crystallites are supported on thesurface with La_2O_3. It has been found by the XRD peak broadening that the average size ofnickel crystallites on the surface with La_2O_3 is much smaller than that without La_2O_3. Thismay be one of the main reasons for the increase of activity and thermostability of the La_2O_3containing methanation catalyst. This idea of modifying support surface by monolayercompound can also be applied to other catalysts.     

EFFECTS OF K_2O AND MnO PROMOTERS ON THE PRODUCTION OF LIGHT ALKENES VIA SYNGAS OVER Fe/SILICALITE-2 CATALYST IL REDUCIBILITY OF K-Fe-MnO/SILICALITE-2 CATALYST

K_2O and MnO are two kinds of necessary promoters to theselective production of light alkenes from CO hydrogenation over silicalite-2(Si-2) zeolite supported Fe catalyst. The addition of both K_2O and MnOpromoters into Fe/Si-2 catalyst leads to a remarkable increase in the COconversion and the selectivity to light oletins. Silicalite-2 zeolite as Fe-MnOcatalyst support can suppress the formation of α-Fe_2MnO_3 or/andα-Fe_(2-y)Mn_yO_3 as Well as α-Fe_2O_3 and/or α-Mn_2O_3, being favorable for(?)ncreasing the dispersion of active metal component. So MnO can promotethe reduction of Fe~(3-) and enhance the capacity of CO adsorption, which canimprove the activity of the activity of the catalyst for CO hydrogenation. While K_2Opromoter is unfavorable for reduction of Fe~(3-) to some degree with formation of Fe~(2-) as a new species after reduction. However, K_2O promoter can enhance the capacity and strength of CO adsorption greatly.So K_2O can alsoimprove the activity of catalyst for CO hydrogenation.     

DECOMPOSITION OF KNO_3/γ-Al_2O_3 AND THE FORMATION OF SURFACE BASE SITES

ＤＥＣＯＭＰＯＳＩＴＩＯＮＯＦＫＮＯ３／γ┐Ａｌ２Ｏ３ＡＮＤＴＨＥＦＯＲＭＡＴＩＯＮＯＦＳＵＲＦＡＣＥＢＡＳＥＳＩＴＥＳ＊ＴｕＭａｉ，ＬｉＤａｔａｎｇ，ＺｈｕＪｉａｎｈｕａ，ＳｈｅｎＪｉａｎｙｉ＊＊（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｉｎｓ...     

STUDY ON DISPERSION SPEED AND MECHANISM OF MoO_3 AND CuCl ON THE SURFACE OF γ-Al_2O_3

It has been shown that many oxides and salts can disperse spontaneously onto supports with large surface area. A typical example studied widely is the disper-sion of MoO_3 on γ-Al_2O_3. However, the research work about the dispersion mecha-nism and kinetics is quite few.     

STRUCTURAL AND ELECTRONIC EFFECTS OF TiO_2 IN CuO-ZnO/Al_2lO_3-TiO_2 CATALYST

The modification effects of TiO_2 towards Cu or CuO in supportedCuO-ZnO/Al_2O_3-TiO_2 catalyst were studied by XPS,TPD and test reaction.XPS showed that TiO_2 additive improved the dispersity of CuO or Cu in cata-lyst.TPR showed that the reduction temperature(Tr)of CuO in CuO-ZnO/Al_2O_3-TiO_2 increased with the content of TiO_2.XPS showed that the Eb valueof Cu in TiO_2 containing catalyst(Eb=993.7 eV) was larger than that inTiO_2 free catalyst(Eb=932.9 eV).These indicate that TiO_2 displayed elec-tronic effect on catalyst.Both structural effect improving the dispersity of Cuand electronic effect weakening the bond strength of Cu-S in catalyst caused theS-resistance of CuO-ZnO /Al_2O_3-TiO_2 catalyst greatly improved.     

OXIDATIVE COUPLING OF METHANE OVER Mn_2O_3-Na_2WO_4/SiO_2 CATALYST Ⅰ.CHARACTERIZATION OF ACTIVE SITES ON THE CATALYST

EPR and Raman spectroscopy have been used to characterize the catalyst. F-centers with EPR parameter of g=2. 0046 form when gas phase oxygen is admitted onto the catalyst reduced with methane at 800℃- Molecular oxygen plays an induced role in the electron transfer from W4 to the oxygen ion vacancy which is produced by methane reduction. Raman spectra give the further evidence for the production of lattice oxygen from molecular oxygen.     

EFFECTS OF K_2O AND MnO PROMOTERS ON THE PRODUCTION OF LIGHT ALKENES VIA SYNGAS OVER Fe/SILICALITE-2 CATALYST I.ACTIVITY OF K-Fe-MnO/SILICALIT-2 CATALYST

The activity and the selectivity to light alkenes of silicalite-2 (Si-2) zeolite supported F'e catalyst tor CO hydrogenation can he improved obviously with the addition of K2O and MnO promoters. The results of CO hydrogenation, CO-TPD, CO/H2-TPSR, C2H4/H2-TPSR and C2H4/H2 pulse reaction over K-Fe-MnO/Si-2 catalysts clearly show that the K2O additive into Fe-MnO/Si-2 catalyst leads to a remarkable increase in both the capacity and strength of the strong CO ad-species that will produce much more |Cad| via their disproportionation at higher temperatures. This results in an increase in the CO conversion and the selectivity to light olefins, and a decrease in CH4 formation. Moreover, K2O can suppress the disproportionate of C2H4 that occurs during the reaction as a side-reaction Meanwhile, the MnO promoter mainly prohibits the hydrogenation of C2H4 and C3H6, which is favorable to enhancing the selectivity to C2H4 and C3H6 and decreasing the formation of C2H6, and C3H8. It is also of interest that MnO has har     

SUPERCRITICAL-PHASE PROCESS FOR SELECTIVE SYNTHESIS OF HEAVIER HYDROCARBONS FROM SYNGAS OVER ARu/Al_2O_3 CATALYST

在Ｒｕ／Ａｌ２Ｏ３催化剂上进行了超临界条件下的固定床费托合成。研究了催化剂孔尺寸、α－Ｃ１４烯共进料和反应温度对费托合成产物分布的影响     

EFFECTS OF BINDERS ON THE PRODUCTION OF LIGHT ALKENES FROM SYNGAS OVER K-Fe-MnO/SILICALITE-2 CATALYST Ⅱ. MODIFICATION EFFECT OF Al_2O_3 BINDER ON CO HYDROGENATION

lntroductionInordcrtoselcctivcl}'produccIightoIcfinsfroms}'ngas.thcbinderusedforimprovingthecatal}'ststrcngthshouldbcfavorabIcforprimary'formingofligl1tolcfinsfroms}ngasandforprohibitingsidereactionsoflightoIcfi.sIll.lthasbccnshownthattheundesirablcstrengthofsilicalitc-2zcolitccanbcimprovcdb}addingbindcrs.Hot`ycver.thcadditionofthcbinder`"illcauscsomcchangcsinthcph}'sical-chcmicalstatcofthecatal}ticactivemetalas``cllasitscatal}ticbcha.io,ll'2I.InourprcviouspaperTiO2wasprovedtobcadcsirablcbi…     

EFFECT OF RARE EARTH OXIDES ON Ni/Al_2O_3 CATALYST FOR THE STEAM REFORMING OF METHANE

Microreactor-chromatography and XRD technique have been used to investigate the proper-ties of Ni/Al_2O_3 catalyst impregnated with rare earth oxides for the steam reforming of methane.Theresults of the study have shown that the stability of catalytic activity and the ability of resistance to ox-idation of high temperature steam are improved.     

INSITUFTIR SPECTRAL STUDY OF THE OXYGEN ADSPECIES ON SrF_2／La_2O_3 CATALYST DURING THE OXIDATIVE COUPLING OF METHANE

ＩＮＳＩＴＵＦＴＩＲＳＰＥＣＴＲＡＬＳＴＵＤＹＯＦＴＨＥＯＸＹＧＥＮＡＤＳＰＥＣＩＥＳＯＮＳｒＦ＿２／Ｌａ＿２Ｏ＿３ＣＡＴＡＬＹＳＴＤＵＲＩＮＧＴＨＥＯＸＩＤＡＴＩＶＥＣＯＵＰＬＩＮＧＯＦＭＥＴＨＡＮＥ￥ＲｕｉＱｉａｎｇＬＯＮＧ；ＳｈｕｉＱｉｎＺＨＯ...     

STUDY ON THE SURFACE MODIFICATION OF NANO-TiO2 BY GRAFTING PMMA／PBMA AND ITS THERMAL STABILITY

The surface of nano-TiO2 was encapsulated with hydroxyl-propyl-methyl cellulose (HPMC), and then cografted with acrylates. Conditions of absorbing and grafting have been studied. Modified nano-TiO2 particles were characterized by FT-IR spectra, TEM and TG analysis. It was convinced from FT-IR studies that both methyl methacrylate (MMA) and butylmethacrylate (BMA) were co-grafted onto the surface of nano-TiO2 particles. TEM images show that the surface of nano-TiO2 particles was successfully modified by a thick layer of film-like polymer. TG results demonstrate that the decomposition temperature of HPMC-g-PMMA/PBMA, which has been grafted onto the surface of nano-TiO2, is 56.9 K higher than that of HPMC-g-PMMA/PBMA.