졸 - 겔법으로제조된복합알루미나미분체의첨가제에의한구조적특성비교

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1 Krean Chem. Eng. Res., Vl. 43, N. 4, August, 2005, pp 졸 - 겔법으로제조된복합알루미나미분체의첨가제에의한구조적특성비교 mkçl *Çym Ç sç kiç Ç **Çl q***, ne e 1 * vvql q nl re r 30 ** d l LNG l ˆ p}e l 973 *** r e 720 ( p r, p }ˆ) A Cmparisn f Structural Characterizatin f Cmpsite Alumina Pwder Prepared by Sl-Gel Methd Accrding t the Prmters Jung-Wn Lee, H-Sung Yn*, U-Suk Chae, Han-Jin Park, Un-Yen Hwang, Hyung-Sang Park, Dal-Ryung Park** and Seung-Jn Y***, Department f Chemical Engineering, Sgang University, 1, Shinsu-dng, Map-gu, Seul , Krea *Divisin f Minerals Utilizatin and Materials, Krea Institute f Gescience and Mineral Resurces, 30, Gajeng-dng, Yuseng-gu, Daejen , Krea **LNG Technlgy Research Center, KOGAS, 973, Dngchun-dng, Ynsu-gu, Inchn , Krea ***Faculty f Envirnmental and Chemical Engineering, Senam University, 720, Kwangchi-dng, Namwn, Chnbuk , Krea (Received 27 December 2004; accepted 13 June 2005) k l s- p pn l k rs m, k ~ rp ~ l p k p lr k r p m. 1,200 Cl eˆ k p lr kr p n ~ rl SiËLa>Ti>BaËCe> Y>ZrËMg p ˆ. e ~ e α-k p rp m 150 Cp l 1,200 Cl l γ- l δ- p k p v p k pl, rp 3m 2 /gp α-k l 71 m 2 /g( r) v v p m. p k pqp e ~ k p n mp e Si- O-Alp p v p l k p rp vleˆ ˆ, ˆ ~ k p n LaAl sp sq p k p pq p vleˆp k pl. ˆ ~ e 1,000 C p l eˆ n ˆ p k l La 2 s sq 1,000 C p l LaAl p pervskite s sq, 1,300 C p l LaAl 11 O 18 p magnet-plumbite s sq p XRDm XPS l p p pl. h Abstract In this research, cmpsite alumina was prepared t add the varius prmters by sl-gel methd and examined its thermal stability. After sintering at 1,200 C, the thermal stability resulted in fllwing rder, SiËLa>Ti> BaËCe>Y>ZrË Mg, in accrdance with adding the prmters. Especially in case f silica-added alumina, a phase transfrmatin temperature t α-alumina increased abut 150 C and after sintering at 1,200 C, it shwed t maintain in γ-frm and δ-frm alumina phase. Als it shwed an increase f surface area frm 3 m 2 /g t 71m 2 /g cmpared with pure α-alumina. In the case f silicaadded alumina, the characterizatin change f this alumina particle resulted in a delay f phase transfrmatin because Si-O-Al bnd was increased when sintered at high temperature. In case f lanthanum-added alumina, there was a sintering delay phenmenn in inter-particles as LaAl structure existed. The existence f lanthanum structure was cnfirmed by XRD and XPS analysis. It appeared n the alumina surface as La 2 structure when it was sintered under 1,000 C, as the pervskite structure f LaAl at abve 1,000 C and as the magnet-plumbite structure f LaAl 11 O 18 at abve 1,300 C. Key wrds: Cmpsite Alumina, Thermal Stability, Silica, Lanthanum, Sl-Gel T whm crrespndence shuld be addressed. sjy@senam.ac.kr 503

2 504 prnë Ë}p Ë vë nlë Ë Ëdt 1. m q l l,, p l v p [1], l Gas Research Institute t ep v pp l p, d, pˆ k tep m q l l v p. rp rm l v rkp p p mn l pn d l l ep s p. l l pl mn q l p eq k tn p vq pp. l l q v v k p 1,000 C p l p v m q trp p. np q n k vv~ p r, r s p p v p l vv~ q nrp n l m. γ-k p r( m /g)p v pv ml ll rp 2 q kr α-k pl rp (5 m 2 /g p ) l vv~ p np l. p Schaperm Ykkwa [2-3]p l 1,200 C e γ-k l α-k p rp p q ll p p v(γ, θ, δ )p v(α )p p pl k q~p l p rp r eˆ. q vp ml kr k rs l p k ~l ~ r ~ l k p ml p r qp rp vleˆp m l p ~ rp ~ lp k p rss r ~p r p m l p e v p [4-5]. k rs p l v k r p v, l l pn q s- p nk l r p p q rp v k p n p k p p n l m t pp l s pq rm, k p pp l ~ p rs p, l p l v d lp pp, p r p lp p p. k rp p l ~ r ~ l p sp sm ~ k s kl ~ r p n m. p k pq l pq ~ sp l l γ-k l α-k p r p rm mq p pn p m. k p lr kr p eˆ p ~ v k, k Š, Š, e, p k r pp [6-9], l l m vv~p qnp v eˆ k p lr kr p v eˆp ml p eˆ p vv~l ~ r ~ l k m r q mp q lr p n e m ˆ p tep lr kr p m p i m g m k Fig. 1. Flw diagram fr high temperature stable cmpsite alumina particle preparatin. Fig. 1p k rp e p, rp v k p p [Fluka AIP, Al(OC 3 H 7 ) 3, Fluka Chemie AG] n l (hydrlysis) t p(plymerizatin/cndensatin) p (peptizatin)[10]p ~ t ~p k s(behmite, γ-alo (OH))p m. pm 90 C, pe 30 p pr r pn l 1,000 RPMp m. kr k sp l l rr (0.07 HCL/Al) l pp v e [11-12]. p llv k s nkl ~ r s ˆl ~ l e. p llv k sp 110 Cl k s 4 C/minp dm pr m v dmeˆ, sm l 1e ve g m Š k ~ r ~ k p p l p p p m. k p r X r (X-ray diffractin analyzer, Rigaku)l p Žq Å p CuKα target, scanning speed 2 /min, 30 kv, 20 ma, 10 2θ 90 scanning range s l m. k p s l k~ rn (FTS-60, Bi- Rad)p -1p 400-4,000 cm l mp, r p v ˆ (BET, Micrmeritics, ASAP 2010) pn l m. k pqp p t rq (SEM, JSM-840A, 5.0 kv)p pn m. k p l ~ rm k p kk l XPS(ESCALAB 220i-XL, VG Scientific Instrument) pn l m.

3 s- p rs k ~p ~ rl p sr y 3-1. z z i m in g l l k p lr p eˆ l lrp kr v k v k, k Š, Š, e, v p ~ l k p lr kr p m. Fig. 2 k ~ r ~ l p rs k 1,200 Cm 1,300 Cl lr kr p XRD p. 1,200 Cl eˆ ˆ ~ k θ- α- p, e ~ k δ- θ- p, v k, d,, p, p ~ el pseud α- α- p ppp k p. 1,300 Cl eˆ nl e ~ k θ- m α- p, ˆ ~ k pseud α- p ˆ p. ~ rp n α- p rp p k p. XRD l p e ~ k m ˆ p ~ k ~ r ~ k l 1,200 Cp ml vv~p lr kr p v ppp p pl. Fig. 3p FT-IR l p l ~ r ~ l 1,200 Cl 1e eˆ k p n 1 3,600 cm 1,635 cm tž l p l p 1 m. l Fig. 2. X-ray diffractin patterns f Pd/cmpsite-alumina accrding t the additin f varius prmters sintered at tw different temperature; (a) 1,200 C, and (b) 1,300 C. Fig. 3. FT-IR spectra f Pd/cmpsite-alumina accrding t the additin f varius prmters sintered at 1,200 C. Krean Chem. Eng. Res., Vl. 43, N. 4, August, 2005

4 506 prnë Ë}p Ë vë nlë Ë Ëdt Fig. 4. BET surface area f Pd/cmpsite-alumina accrding t the additin f varius prmters sintered at 1,200 C and 1,300 C. Fig. 5. Cmparisin f BET surface area and pre diameter f Si dped alumina particles sintered at 1,100 C accrding t the varius Si amunts. 3,600 cm tž l ˆ s rs re 1 p Al-OHp e v l p p, 1,635 cm 1 tž l ˆ š v l p p [13]. e ~ k m ˆ ~ k p n Al-OH ˆ p k Al-OHp p sq p m, ~ r ~ k p nl Al-OHp p p sq v k p k Fig. 2p XRD m v pseud α- α- p v ppp k p. e ~ m ˆ ~ k p nl kp OH p k ~ rl p r s γ- p v p p k p. Fig. 4 l ~ rl 1,200 Cm 1,300 Cl k p v ˆ l p rp ˆ p. m l p 1,000 C p p m l p vv ~ p l p r rp n l, k 1,200 C el 5.1 m 2 /g, 1,300 C el 2.1 m /gp r p v 2 p. e ~ k 1,200 C el 71 m 2 /g, 1,300 C el 6.5 m 2 / gp r p v p, ˆ ~ k p n l 1,200 C el 28.9 m 2 /g, 1,300 C el 7.9 m /gp 2 r p v p. p k m ~ r ~ k l rp v ppp k p, kp XRDm FT-IR p p p Si z i m sszm in Š y Fig. 5 k l e ~ e ~ l e ~ k p s p m p e s l rp 2wtÍ(Si/Al) ~ k p n v rp v p kp e ~ e p rp lp ˆ, 2wtÍ ~ p n q p v pl. e l 2wÍp e ~ s p m. Fig. 6p 1,100 Cl k m e ~ k Fig. 6. Nitrgen adsrptin-desrptin istherms f pure alumina and Si dped alumina at 1,100 C accrding t the varius Si amunts. k p v ˆ m p. k m e ~ k BDDT[14] 5 vp rp m tl mespre(2-50 nm by IUPAC)p p ˆ Sq p m p ˆ pp k p. d edp ˆ de Ber[15] rp 5 v t, e ~ k qp pq p vl p p ˆ~p l p p kp p ˆ Type Ep, k pq p pvl p l e kp p ˆ Type Al. P/P=0.2 p v p p k 15, 1 wtí e ~ k 25, 2m 5wtÍ e ~ k 40(cm 3 N 2 gas at STP)p p k 2wtÍm 5wtÍp e ~ e vv~l j n rp v ppp k p. k m e ~ k ˆ l p n v p Ž p p, p p p v p p ppp m p. p p Fig. 7l

5 s- p rs k ~p ~ rl p sr 507 Fig. 7. Pre diameter distributins f pure alumina and Si dped alumina at 1,100 C accrding t the varius Si amunts. Fig. 9. XPS Si 2p cre level spectra f Pd/Si dped alumina sintered at tw different temperature cnditins; (a) 1,000 C and (b) 1,200 C. Fig. 8. SEM image f varius aluminas; (a) Si dped alumina sintered at 1,000 C, (b) Si dped alumina sintered at 1,200 C, (c) Si dped alumina sintered at 1,300 C, and (d) pure α-alumina at 1,200 C. m p, e ~ k p nl k 7-8 nmp p p k pl, k p nl nmp p 70 nmp p rp p v p p. e 2wtÍ 5wtÍ ~ k p p p e l r 2wtÍp e ml kr vv~ rr kp ~ l v. vv~p s p p r n tn np tp p l k p s m p rp } tn. Fig. 8p 1,000 C, 1,200 C, 1,300 Cl k m e v k p SEM(JSM-840A, 5.0 kv) vp. 1,200 Cl k 1,300 C e v k l pqp ˆ. p e ~ p k pq p p l k α- p rp p vleˆ p. Fig. 9 Ž v e ~ k 1,000 Cm 1,200 C l e Si 2pp cre levelp XPS p. p m 1,000 Cl 1,200 C m p n ev p Si-Op p ˆ p v, binding energy evl ev v p pl. p m pl e tl p p v, e ~ p n ml Si-O-Alp p v l k p ml p p lr ~ p p. Table 1l p, Al 2p cre levell m pl Al-Op p ˆ binding energy 73.7 ev l 74.2 ev v p p, I /I Si(Si-O) Al(Al-O)p 1,000 Cl 1,200 C m mp 4.4 v p p p. p 1,000 C p e e p k tp m l e p p p. p Al-O-Si p v p l k l k p t pp Al-OH p l k p rp v leˆ ˆ. Krean Chem. Eng. Res., Vl. 43, N. 4, August, 2005

6 508 prnë Ë}p Ë vë nlë Ë Ëdt Table 1. XPS Si 2p and Al 2p cre level binding energy and intensity rati f Pd/Si-Al 2 catalysts at different temperature Binding energy (ev) Intensity rati Prepared catalyst Si 2P (Si-O) Al 2P (Al-O) I Si(Si-O) /I Al(Al-O) Pd/Si-Al 2-1,000 C Pd/Si-Al 2-1,200 C La z i m sszm in Š y Fig. 10p m l ˆ p ~ k p XRD p. Bettman [16]p k l ˆ ~ e m 800 C p l La 2 sq, p p m l LaAl sq. e l La 2 p n γ- δ-k m p pl XRD l p ll, pp XPS l La 2 p sq p m. Schaper [17-18] k l p lanthanide aluminatep pervskite-type(laal ) sp sq rp k p lr kr p veˆ npp m. LaAl LaAl 11 O 18 (magnet-plumbite s) eˆ r ~ l p p k r p. l l ˆ ~ k p n 1,200 Cl el LaAl s p p m. 1,200 Cl α-k m LaAlp sp p l r sp p v mp, 1,300 C p l rp r p p magnetplumbite s p vv~ p p vp lt p. Fig. 11p Ž v ˆ ~ k p m l l p La p ˆm s XPS p. p p La 3d 5/2l p l v m 600 Cl 1,200 C pl , , m ev l vp v pp k p. La 3d 5/2p l v v p ˆ p v, v ˆ tl qp v p p. La 3d 5/2l La 2 p ˆ p l v 833.7, Fig. 10. X-ray diffractin patterns f La dped alumina sintered at varius temperature k Fig. 11. XPS La 3d 5/2 cre level spectra f pd/la dped alumina sintered at varius temperature. Fig. 12. XPS O 1s cre level spectra f pd/la dped alumina sintered at varius temperature , evl ˆ. 600 Cm 800 C l ˆ La 3d 5/2p l v La 2 p ˆ pv, 1,000 Cm 1,200 C l La 2 p ˆ l v ƒvp k p. p 1,000 Cm 1,200 Cl La 2 m l v ˆ p p v p. Fig. 12l O 1s cre levelp m l O 1s tp ˆ l l v 528.9, 528.9, 529.2, ev v p p. O 1s cre levell p l vp v tl p q p p. O 1s l La 2 p ˆ p l v 528.4, ev tl ˆ. 600 Cm 800 Cl l p O 1sl l v p La 2 p ˆ p l v v pp 1,000 Cm 1,200 Cl La 2 p binding energy p ˆ p v ppp m p. Table 2 m l Ž v k p O 1s

7 s- p rs k ~p ~ rl p sr 509 Table 2. XPS O 1s cre level binding energy and intensity rati f Pd/ La-Al 2 catalysts at varius temperature Prepared catalyst Binding energy (ev) Intensity rati O 1S(La) O 1S(Al2O3) I O(La) /I O(Al2O3) Pd/La-Al C Pd/La-Al C Pd/La-Al 2-1,000 C Pd/La-Al 2-1,200 C cre levell p XPS l p l vm ˆ p. m pl O 1sp ˆ m k p l v v p p, (I /I O(La) O(Al 2 ) v ppp ˆ p. p ) m pp p k p r rp ˆ p v p lt. Fig Table 2p s Ž v ˆ ~ k p n 600 Cm 800 C nl ˆ p La 2 p ˆ sq p p pl. 1,000 C p p e ˆ tl q kv k p t ˆ p v p, prp XRD v La 2 LaAl sq srp 1,300 C p l LaAl 11 O 18 s p p pl. p Chen [19] p ˆ ~ k p XPS l O 1sl La ev, LaAl evp p vp p m p p k pl. 4. l l sl-gel encapsulatin p rs e ~ k m ˆ ~ k k m lr kr p p k v ~ r ~ k l ml p s lr kr p n eˆ pp m. (1) vv~l m kr p l l ~ r ~, Š k Š l l e m ˆ ~ k ml p kr p q n p k pl. l l ml kr p eˆ ~ r p p (SiËLa>Ti>BaËCe>Y>ZrËMg) m kr p v. m kr p e ~ p α-k p rp m 150 C p l 1,200 Cl l γ-k l δ-k p v p k pl, rp 3m /gp 2 k l e ~ k p n 71 m 2 /g ( r) v v l m p e. (2) ˆ ~ k p rpe sr p pl. XRDm XPS l p 1,000 C p l ˆ p k l La 2 s sq 1,000 C p l LaAlp pervskite s sq, 1,300 C p l LaAl 11 O 18p magnet-plumbite s sq p p pl. k p rp vleˆ pp LaAl sp sq p l k p pq p vleˆp k pl. e ~ k p n mp e Si-O-Alp p v p l k p rp vleˆ ˆ. p l rs k m l n p rn p r, p l p v p l pn. l l v p 2002 q v lp p p lp, pl. y 1. Lafarga, D., Lafuente, A., Menendez, M. and Santamaria, J., Thermal Stability f γ-al 2 /α-al 2 Mesprus Membranes, J. f Membrane Science, 147(2), (1998). 2. Schaper, H., Desburg, E. B. M. and Reijen, Van, L. L., The Influence f Lanthanum Oxide n The Thermal Stability f Gamma Alumina Catalyst Supprts, Applied Catalysis, 7(2), (1983). 3. Ykkawa, T. and Kleppa, O.G J., A Calrimetric Study f the Transfrmatin f Sme Metastable Mdificatins f Alumina t α-alumina, J. f Physical Chemistry, 68(11), (1964). 4. Rssignl, S. and Kappenstein, C., Effect f Dping Elements n the Thermal Stability f Transitin Alumina, Internatinal J. f Inrganic Materials, 3(1), 51-58(2001). 5. Xue, L. A. and Chen, I. W., Influence f Additives n the Gammat-Alpha Transfrmatin f Alumumina, J. f Materials Science Letters, 11(8), (1992). 6. Oudet, F., Vejux, A. and Curtine, P., Evlutin During Thermal-Treatment f Pure and Lanthanum-Dped Pt/Al 2 and Pt- Rh/Al 2 Autmtive Exhaust Catalysts-transmissin Electrnmicrscpy Studies n Mdel Samples, Applied Catalysis, 50(1), 79-86(1989). 7. Church, J. S. and Cant, N. W., Stabilizatin f Aluminas by Rare-Earth and Alkaline-Earth Ins, Applied Catalysis A: General, 101(1), (1993). 8. Gnzalez, R. D. and Zu, W., Thermal-Stability f Silica-Sup- Prted Palladium Catalysts Prepared by the Sl-Gel Methd, Applied Catalysis A: General, 126(2), (1995). 9. Ozawa, M. and Kimura, M., Effect f Cerium Additin n the Thermal-Stability f Gamma-Alumina Supprt, J. Mater. Sci. Lett., 9(3), (1990). 10. Y, S. J., Lee, J. W., Hwang, W.-Y., Yn, H.-S. and Park, H.-S., A Study n the Peptizatin Reactin Accmpanied with γ-al 2 Particles Preparatin by Sl-Gel Methd, HWAHAK KONG- HAK, 36(5), (1998). 11. Yldas, B. E., A Transparent Prus Alumina, Ceramic Bullentin, 54(3), (1975). 12. Yldas, B. E., Alumina Sl Preparatin Frm Alkxides, Amer. Ceram. Sc. Bull., 54(3), (1975). 13. Peri, J. B.,G Infrared and Gravimetric Study f the Surface Hydra- Krean Chem. Eng. Res., Vl. 43, N. 4, August, 2005

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