1、50 null1 厦门大学学报(自然科学版) Vol.50null No. 1null 2011 M1Journal of Xiamen University (Natural Science) Jan. 2011nulls Pdb4 CO ?王昭文,陈明树* ,万惠霖(0 v,%8V SE L i,? b 3SE L i,y0 361005)null nulll : 2010null05null26 “:SE1 S “(20873109, 21073149); S/973 “(2010CB732303); S/ v “(309019);p V(200803841011);y 81 S “(2
2、008J0168)*YT: chenms xmu. edu. cnK1:!s b4 s 1 % KL 1 m .ZE!B“ Pdb4, I 8Pdb4CO ?.?CYd - z8Pd/TiO2b4Pd/ SiO2Pd/ Al2O3b4, i/VC zCO, O MO2Hq/CO VPd/ TiO2b4V ()Q 3B CO2.s kaCO ; 6TV Pd/TiO2b4 Pds Pd0 Ti,i8Wi 8“COh“2# _ COh“3 .t MCOK L Aub4, ab4# Aub4 y.Pda8 H9 VVCCO, Luo4null5 I 8Pdb4CO?,PdCeO2Wi“xT,MQHq
3、/, Pd/CeO2b4Pd/ ZrO2aPd/Al2O3aPd/ TiO2aPd/ZSMnull5Pd/SiO2, CO 6(COnullTPR)T ,s PdO Q.8 6?Cs0 8Pdb4 A b4,Pds b4M1. Zhu7 Pd/ CeO2b4/CO1YVPdnullCe COCeO2V . Baidya8CeO2$ Ce1nullx Snx O2aCe1nullxZrxO2Ce1nullx Tix O2Pdb4CO ?,b4Ce0. 78Sn0. 2Pd0. 02O2nullnullPd2+ 0aM,yN/CO VCO2, H V ?Q: n5 Pd2+CO #Q 3CO2,b
4、4$ J, MO2| 8M, Pb4 3.Ce1nullx SnxO2 Ce1nullx ZrxO2Ce1nullxTix O2%i ? ,yNPd .DCOPdb41 CeO28,TiO28! CO ? Pd/TiO2b4,iSiO2aAl2O381, Pd/ TiO2b4 y.1 null Ls1. 1nullb4!|B X zYd Pd( acac) 2J LBrukerVertex 70V b =; N , Q64Q,sO q4 cm- 1. V e raa l,KBr3 . L -b4H2 r/300 null1 h.H2nullTPR M NLs, V( H2) nullV( Ar
5、) = 5 null95T , _ ,AY?%nullAW“ V 3H2O. TPR -b4300null(V(O2) nullV( Ar)= 5null95)30 min.2 null LT) 2. 1nullb4 N8Pdb4CO m1 U.Vm V APd/TiO2b4Pd/SiO2Pd/Al2O3, i/VCBCO.Hq/COPtBB v, , O2 /v | %CO,yNCOY$ B1Q9 .DO2 l R Pd 10 ,Al2O3Pd , 0 “ hl79F,NQads= 373- 14null d,TQads ( kJ/mol), d , 0(nm). l, v, O2 11 .
6、2. 2null BETs T3b41V # s V1 U.1 Pd/SiO2aPd/Al2O3Pd/TiO2b4,1V GQ, b41V %m1 null8Pdb4COFig.1null Lightnulloff curves of CO oxidation over Pd catalystswith various supportsV1nullb41V s Tab.1null Surface area and metal dispersion data of Pd catalystswith various carriersb41V / (m2 null g- 1) Pds a/%1% P
7、d/ SiO2 382.7 27. 21% Pd/ Al2O3 165.7 75. 11% Pd/ TiO2 149.5 37. 9null:a.L !O/ Pd= 1, O2+ 2Pdnull2Pdnull O.1y . Pd/ Al2O3aPd/ TiO2 s vPd/ SiO2b4, Pd/Al2O3r75. 1%.2. 3null CO FTnullIR3b437 null CO FTnullIRm m2 U. Pd/ SiO2aPd/Al2O3Pd/ TiO2b4r CO sY1 330, 3 192,2 926 Pa, h“ MCO lY, CO m h“ MCO l .Vm V
8、A, Pd/SiO2, Pd/ Al2O3Pd/TiO2 3b4sY2 0871 954 cm- 1,2 0801 934cm- 1,2 0821 901 cm- 1)C CO l. 2 080 2 087 cm- 1COPd0 L T ( linenullarly bonded, Pd0nullCO); 2 000 1 900 cm- 1COPd0 B T ( isolated bridged, Pd2nullCO) 7, 12 ,3b4 Pd ( (Pd0) Ti.1 3b4, Pd/SiO2b4 CO B T M vL T ,7Pd/ Al2O3aPd/ TiO2b4MQ t , COL
9、 T M Av B T , Pd/Al2O3Pd/TiO2b4 Pds z,M )Ha Pd0,null66null0 v(1 S) null null null null null null null null null null null null null null null null null null 2011 Mm2null Pd/ SiO2aPd/Al2O3aPd/ TiO2b4CO h“ MCOIR mFig.2 null IR spectra taken after saturation adsorption and gasCO was subtracted from the
10、 spectrum,for CO adsorptionon Pd/SiO2,Pd/ Al2O3 and Pd/ TiO2 catalysts7Pd/SiO2b4 Pd R v,)Ha Pd0 M .Pd/ TiO2b4 “ B Pd0 L T( 2 082 cm- 1, Pd0nullCO) B T(1 901 cm- 1,Pd2nullCO) ,C VB CO22 3632 337cm- 1 l,# ( carbonate species,OCO) l(1 5681 351 cm- 1) 7 .37null MO2Hq/, Pd/ TiO2b4COCO2 3,b4 N4B,tTV CO,9
11、V ? 1, V ?Pd8TiO2xT,Pd CO,7TiO2V O24. CO C , V ? 3CO2 .m3Pd/TiO2b41 330 PaCO r/6VIR m. “b4 6,L Ta B TCO (2 0821 901 cm- 1) (hl,i O _o M(V2 082 cm- 1 null2 071 cm- 1); l( 1 5681 351 cm- 1) 6Ah ,N H MCO2 l(2 3632 337cm- 1)v9 ,V 6 H s 3CO2. Luo13 Pd/ MOxnullCeO2 ( M = Mn,Fe,Co,Ni,Cu)b4 , ( bidentatecar
12、bonate,1 5871 285 cm- 1) CO 3CO2W. CostelloV 14 Au/Al2O3b4 CO9V W8: n5CO Aunull OHoB _, _ $ Au00 J O3 , s VCO2AunullOH.V s V,CO Pd/TiO2V ,M/ VV ()Q 3CO2; Hs Ti, “6CO2.2. 4null H2nullTPRTm4b4H2nullTPRm. Pd/SiO2b4 PdO 10 null 7 S$, H70 nullPCH2.70 80 null nullnullPdHSs12, 15null16 , nullnullPdH$ vR Pd
13、B+12, 16 .Pd/Al2O3Pd/ TiO2b49(sY4575 null )C PdO,2b4 i C, 2b4 Pd R l12, 16 ,s . Pd/TiO2b4“ 45 nullPPdO,310 nullP)9CH2h,PdOnull67null1 null null null null null null null null null null null null null null nullr:s Pdb4 CO ?m5 nullb4300 null1 hTEMmFig.5 null TEM images of different catalysts after H2 r
14、eduction at 300 null for 1 h(45 nullP)M1_M,TiO2(528 nullP)M1_M, 1TiO2H2h v, VB 8Wi MTPdOx4, 16 .2. 5null TEMTm53b4TEMm,b4XmS.DSiO2,Al2O3, TiO2Pd, R TEMm (1 A8Q, R vlG !ZE817null19 .V3b41 V A A, Pd/ SiO2b4 3M Pd , R ,1“5 6 nm,7Pd/Al2O3Pd/TiO2TEMm 4 An b PdR , V ? Pd28 s z, 3 Rl.tTBV ,Pd - z8!Pdb4 ?s
15、, Pdb4.TEMTV Pd/Al2O3Pd/ TiO2b4 Pd ( zs , Pd/Al2O3Ts ( ),7Pd/TiO2s si z,B V ? yTiO21 , Pd/TiO2 MO2i/ ?CO 3CO2(nm23), b H V ?s, ,9s 9 .8 I n,Pd/TiO2CO V ? Pds 8TiO2 v( # T, HTiO28 ?4Q,YV8FsxT,COPd , “TiO2.3 nullnull 8Pdb4, Pd/TiO2 ?Pd/Al2O3aPd/SiO2b4, i/ bCO ? . s aCO FTnullIRH2nullTPRT Pd/TiO2b4Pds
16、1,7 OCO Vb4V ()Q 3CO2, Pd/TiO2b4 COyB, V ?CO3CO2W.Pd/TiO2b4 i8W MTPd, V ? 9B D. ID: 1 null Yamaura H,Moriya K,Miura N,et al. Mechanism of sennullsitivity promotion in CO sensor using indium oxide andcobalt oxide J . Sens Actuators B, 2000, 65( 1/ 2/ 3): 39null41. 2 nully , , .Aub4 i/COh“ J . ,1996,1
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28、pported Palladium CatalystsWANG Zhaonullwen, CHEN Mingnullshu* , WAN Huinulllin( State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratoryfor Green Chemical Productions of AlcoholsnullEthersnullEsters,College of Chemistry andChemical Engineering, Xiamen University
29、, Xiamen 361005, China)Abstract: In present studies,a series of oxidesupported palladium catalysts weresynthesized using various methods to achieve abetnullter dispersion of the active component. CO oxidation was selected as a probe reaction to examine the catalytic performance. It wasfound that Pd/
30、TiO2 catalyst prepared using palladium(II) acetate as a precursor exhibited high catalytic activity for CO oxidation atroom temperature,which activity is much higher than those on Pd/ SiO2 and Pd/Al2O3 catalysts. Innullsitu Fourier transform infraredspectroscopy (FTnullIR) reveals that CO can react
31、with surfacelattice oxygen of TiO2 to form CO2 in the absence of gas O2 on the Pd/TiO2 catalyst. Comparative studies using BET, O2nullchemisorption, innullsitu FTnullIR of CO adsorption and temperature programmed renullduction (H2nullTPR) techniques were carried out in order to elucidate the relatio
32、nship between thestructure and activity for CO oxidanulltion at low temperature. Metallic Pd was found to behighly dispersed on TiO2 and Al2O3 support surfaces. A relatively high temperanullture reduction peak observed in H2nullTPR suggests a strong interaction between Pd and theTiO2 support. The or
33、igins of the high acnulltivity for CO oxidation on Pd/ TiO2 at near room temperaturemay come from the highly dispersivePd and the strong interaction benulltween Pd and support.Key words: CO catalytic oxidation; palladium;supported catalysts; innullsitu spectroscopynull69null1 null null null null null null null null null null null null null null nullr:s Pdb4 CO ?
