Synthesis, Characterization and Catalytic Properties of Titanium … · 1 HWAHAK KONGHAK Vol. 40,...

HWAHAK KONGHAK Vol. 40, No. 1, February, 2002, pp. 1-8(Journal of the Korean Institute of Chemical Engineers)

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Synthesis, Characterization and Catalytic Properties of Titanium-containing Zeolite Beta Catalysts

Bo-Sang Yoon and Wha-Seung Ahn†

School of Chemical Science and Engineering, Inha University, Inchon 402-751, Korea�Received 17 May 2001; accepted 26 October 2001)

� �

�� (Ti-beta) � � 5�� !" �� #$ %&

2�� '() grafting��$ �*+, �* ��- ./ 0� 1� 23+45. 67 � 8 UV-Vis 9:;-� ��

� <=3* >- ?@AB CD+� ��- EF+� 220 nm8 G�H�� IJAK$L, grafting MN OP QR

ST8 TiO2 cluster- TU+� 240-320 nm8 G� H�� V IJAK5. WX Y=� dry-gel �� seed� �%& OP

50 nm+, Z[ \3]8 ��- 8& TC ��Q TiO2/SiO2 xerogel \3]� �%& OP� 200 nm, ̂ _ `aT

��-b� 2-5µm8 cd Y= ST� Q�>K$L, `=] WX- e& �fg Ti-beta(F−)>Ti-beta(seed)>Ti-Al-beta

(xerogel)>Ti-Al-beta(dry-gel)>Ti-Al-beta(conventional)8 hb *�AK5. Cyclohexene8 epoxidation ijg Ti-Al-beta(conventional),

Ti-beta(seed)>Ti-Al-beta(xerogel), Ti-Al-beta(dry-gel)>Ti-beta(F−)8 hb \kf Q�l$L, epoxide- e& mn�g Ti-

Al-beta(xerogel)<Ti-Al-beta(conventional)<Ti-Al-beta(dry-gel)<Ti-beta(seed)<Ti-beta(F−)8 hb o�+45. Epoxide8 mn�

g �pq� �r� st8 u�� Xv- wx" yz" {U| � }K5. Cyclohexene8 \kf� epoxide8 mn�g 6

7 � -b CH3CN" % �%| ~� CH3OH �5 �� Q�l5.

Abstract − A critical evaluation of synthesis recipes reported for the large pore zeolite Ti-beta was conducted after a series of

titanium containing zeolite beta were prepared by five different hydrothermal synthesis and in two post-synthetic graftingmethods using alkoxide or metallocene as a titanium precursor. All Ti-beta prepared by different synthesis routes showed a nar-

row charge transfer band centered at ca. 220 nm in UV-Vis spectra, typical of Ti sites isolated in zeolite framework. For those

prepared by grafting, the absorption band at 240-320 nm attributed to nano-sized TiO2 clusters were also detected. Particle size

of Ti-Al-beta(dry-gel) and Ti-beta(seed) were below 20 nm; Ti-Al-beta(conventional) and Ti-Al-beta(xerogel) below 200 nm;

and Ti-beta(F−) ca. 2-5µm. Yield of zeolite crystals decreased in the order Ti-beta(F−)>Ti-beta (seed)>Ti-Al-beta(xerogel)>Ti-

Al-beta(dry-gel)>Ti-Al-beta(conventional). For cyclohexene epoxidation, conversions varied in the order Ti-Al-beta (conven-

tional), Ti-beta(seed)>Ti-Al-beta(xerogel), Ti-Al-beta(dry-gel)>Ti-beta(F−) with epoxide selectivity in the order Ti-Al-beta(xerogel)

<Ti-Al-beta(conventional)<Ti-Al-beta(dry-gel)<Ti-beta(seed)<Ti-beta(F−). The epoxide selectivity was affected by aluminum

content and hydrophobicity of the material. Cyclohexene conversions and epoxide selectivities were higher in aprotic CH3CN

solvent than in CH3OH.

Key words: Ti-beta, Hydrothermal Synthesis, Grafting, Cyclohexene Epoxidation

1. � �

�� /��(redox)��

� � �� !"� #$ "% &'( )*+, -.[1, 2].

/ 0 123 �� 4�56 123 789� �-1(TS-1): ;

��<=> ��? %$ @A�BC� DEF GH ��!"�I

HJFK? L �M N, -.[3]. $O TS-1��P AQ �� R

M SAT 0.53-0.56 nm ��? $�+U -KV? SAT L @AWX

� !"�IP !"C &�Y -P �� RM �Z? [�\I ]

U^ < _KV? !" `� ab+ cP d�Y -.. e�I R

MSAT 0.7 nmf beta gh� �� 123 i redox��†To whom correspondence should be addressed. E-mail: [email protected]

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2 ��

a),

y-

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)-

4�56 WXj �� #$ kg� lmn opT -.. qrf�

Corma/s�IP 12-membered ring channel� 3t� RMgh> T

, RMSAT u 0.7 nmf �� v2� 123 wZ gh 4�

56 ��> �hxy WX SAT TS-1� RMz. L cycloalkane,

cycloalkene, cycloalcohol� ��!"� F%$ {; TS-1z. |<$

{;> } < -~.P kg> '�x�.[4]. /�� Ti-betaP <�

B� 5 !" )G� #$ �� {�� <� �,, w!Ff <

�B� ��IP v2 gh> }A �\I w�� N�3 !

�5 opx�.. e�I gh �� N�3 ��K?� =� �

8 � Brönsted �Y '�xy olefin epoxidation� �| !" �A�

�� epoxide� ring opening ab+U glycol ��+, %�(�

��)� !"xy l ��C glycol mono-ethers � glycol di-ethers?

�� ab+V? epoxide� #$ DE� � �x.. Mobil: 1992

� � � ��&��> gh ¡�? ¢%xy G� �£¤¥� e

� 2.0-20 nm� ¦w$ wt�F §¨� � gh� �h©U> ªP

MCM41 �P w«� ¬? WXj> B�xy '�x�.[5]. ®

�h©U WXj�� 123 ��5¯� H#FK? L @AC� �

�!"� °;F �P ±�²³ Ti-MCM41[6] B�+~K´, / �

3t�Ff RM gh> ª, -P Ti-MCM48[7], 0� ��&��>

%$ Ti-HMS[8] i� .�$ 123 �@ �h©U WXj ��T <

�B� µ ��8 ¶·� �\ B�+~,, A2 .¸ � ��K? 4

� 56 kg {;� H¹<T '�+~.. /�� redox �h©U W

XjP L @AWX� !"�P °;Ff !�, �� º RM»

� WX �� ¼½� {y+U ¾�� 789� ¿¢xV? À<�

H#FK? Á,, <�Â�� K´, n-hexene� epoxidation; Ã

;�� <=> ��? xP !"�IP TS-1 � Ti-betaz. !

"� ÄUP ÅK? z,+~.[9]. ÆCº� #$ �A� �AT

UÇ �� T�È: � �� z,� �%]: �h©U Cº� ©�

� redox�� !" )G � %É 'Ê� ¢ËT ÌÍx´ {Î TS-

1� oFn Ï$ ,AÐ� redoxWXj? MJF T4T Á: Cº:

²Ñ ÉÒx c, -., ÓÔx, -.[10]. 1998� Õ��I Ö�

� TOCAT3�I CALTECH� Davis ×<P HJFK? ZTT4T Á

: @A �gj� B�� -U Ò� B�+P MCM�� RM: Ø

¾ S´, �= 10-12Ö? g�� &�� \¹xP RM� redox

WXjT ÙÚÑx.P '�> x, -.[11]. Û$ Delft# � Sheldon

: redox WXj �� #$ ÜÝFf ÞT> �\IP Õw$ hß�

I Ã: !" AàK? .�$ ��> á× kg$ {;T opx.

, âãx, -.[12].

Ò�ä z,� Ti-beta�� B� Ý« kg�IP w!Ff <�B

�·� �$ Ti-Al-beta[4, 13-15], TiO2/SiO2� xerogel� gh ¡�>

ßh �å56 æ <�B� �8xy }: Ti-Al-beta[16], dry-gel ¶·

K? B�$ Ti-Al-beta[17, 18], seed> %\I <�B�$ Al-free Ti-beta

[19-20], ç� W�A�I <�B�$ Al-free Ti-beta[20, 21] i �Â

x�K�, B�$ �� C� t T ��x´, B�¶·� #\I

ÜÝFK? è�Y éên < -P á× kgP Së Zì$ Hí

.. Û$ 123 �@ �h©U WXj ��I 5�+~î ��8 �

ï¢ �[22]� �ð?ñ[23] grafting ¶·� �$ Ti-beta B�� #\

IP z,� ÙT _.. Q kg�IP 123 �@ �� v2 �

�> dò� z,� .�$ redox WXj B� ¶·]� e� �hx�

.. �h$ Ti-beta� <�, 123� gh � 4� ��, B� 5 �N

�3 óT@¾� ��º� e¸ !" ��, !" 5 %�� ô¡

i kgxy �� !"� #$ Ti-beta� "%TÐ�� #\I Ü

ÝF h¢kg> <bx,X x�..

2. � �

�� v2� B�� -U 789�K?P colloidal silica(Ludox

HS(40, 40 wt%, Dupont), fumed silica(Aerosil 200, 99 wt%, Deguss

tetraethyl orthosilicate(TEOS, 98%, Aldrich), �N�3�K?P sodium

aluminate(NaAlO2, 97 wt%, Junsei chemical co.), aluminum nitrate nonah

drate(Al(NO3)3 9H2O, 98%, Aldrich), aluminum isopropoxide([(CH3)2CHO]3Al,

AIP, 98%, Aldrich), metal aluminum(99.9%, Merck), 123�K?P

titanium ethoxide(TEOT, Ti-20%, Aldrich), titanium butoxide(TBOT, 98%

Aldrich), titanium isopropoxide(TIP, 98%, Aldrich), bis(cyclopentadienyl

titanium dichloride(BCTD, 99%, Aldrich)> ¢%x�.. gh ¡�?

op$ @A � �K?P tetraethyl ammonium hydroxide[TEAOH, 35 wt%

solution Aldrich, Na<2 ppm, K<0.5 ppm)] ¢%x�.. <� B��

¢%� 5u� h�: Table 1, grafting� ¢%� !"C� h�: Table

2� ¨¨ �8x�..

2-1. Beta��

��8 grafting ¶·K? 123 �@ ��> �hxA �\I |D

õ<$ �� v2 WXj(SiO2/Al2O3=25)> �hx�.. Ludox

HS-40� TEAOH%G ×!x�I ö: ‘%G 1’ �hx, NaOH(97%,

Table 1. Substrate molar composition of zeolite beta synthesized

Al2O3 Na2O TiO2 SiO2 TEAOH HF H2O2 H2O

Al betaNano Al betaTi-Al-beta(conv.)Ti-Al-beta(xerogel)Ti-Al-beta(dry-gel)Al-free Ti-beta(seed)Al-free Ti-beta(F−)

0.040.02

0.002540.005

0.00152Al of seed

-

0.056---

0.0051--

--

0.01530.01530.01530.01530.0153

1111111

0.360.560.548

0.0041 mole/(g xerogel)0.440.550.548

------

0.548

----

0.0610.3330.333

17.56.5

15.740.134 mole/(g xerogel)

Steam source6.6677.625

Table 2. Substrate molar composition of Ti-grafted zeolite beta

SiO2/TiO2 Al-beta(SiO2/Al2O3) Titanium isopropoxideBis(cyclopentadienyl)-

titanium dichlorideIsopropyl alcohol

Chloroform Triethylamine

1.5% alkoxide1.5% metallocene5% alkoxide5% metallocence

63631919

1.5 g(2.431×10−2 mole)1.7 g(2.76×10−2 mole)1.5 g(2.431×10−2 mole)1.7 g(2.76×10−2 mole)

3.86×10−4 mole(0.113 g)

1.28×10−3 mole(0.375 g)4.38×10−4 mole(0.113 g)

1.453×10−3 mole(0.373 g)

150 ml

150 ml170 ml

170 ml

0.327 g

1.086 g

�� 40� �1� 2002� 2�

� �� 3

Õ�� )� NaAlO2� ‘%G 2’> àá$ .÷, ø 5ù )ø 15úÕÂ

×!xy û�( %\56 � ×!; �ü ‘%G 2’> ‘%G 1’� II

( FTx�.. ¦w$ ý* gel? }Ua þBC 125úÕÂ aging

56 � ÿ��K? �� 8$ 100 ml autoclave� �� .÷ 433 K

�I 5wú B�x�.. B�� !"AP �¨56 � ��W8A>

%xy )GK?Z� �� > �<x,( x ‘y;’), pHT 8-9T +

� 3t �<> %xy R�xy( x ‘R�’), 353 K�I ßh( x

‘ßh’)56 � 550oC�I 65úÕÂ MAW�A�I =�x�.. Û$

seed? ¢%xA �$ � SA v2 WXj> ��8 ��

x�I �hx�.. �� N�3 W� TEAOH %G� 45úÕÂ

×!x�I %\56 ‘%G 1’ �hx, Aerosil 200 TEAOH %G

� %\56 ‘%G 2’ Ï]~.. %G 2� %G 1 ×!x�I FT

xy û�( ¦w$ %G +ë $.. � }Ua %G� Y�P �

�8 � ��xy }Ua %Gz. �� .. %G 60 rpm

K? ×!x�I 135oC�I HA$ <�B� ;�� e� B�x�,,

Õw$ y;, R�, ßh, µ =� ;� `�..

2-2. Ti-beta ��

2-2-1.�ï¢ � GH �gj?Z�� w!F Ti-Al-beta <�B�

TEAOH%G� TEOT ×!x�I $ ¶�� ( öU l, 10

W ÕÂ hydrolysis56 � Aerosil 200 w�$ ×! �� x�I ö

Ul, 15W ÕÂ �T? hydrolysis56.. TEOTP MA 0�I ��

ë hydrolysisT ab+U TiO2? ��+V? isopropyl alcohol%G�

1/10� � á? %\5�I ¢%x�, !" gel àán �P )� ;

� glove box�I �8x�.. Aluminum nitrate nonahydrateP �

<� %\56 � ��( ×!x�I ��( %G öUl, %G

¦wxë �ä ×!x�.. !"%G 25úÕÂ 343 K�I T

�xy isopropyl alcohol �`5�l,, � A�� ZìW� C

z!\à.. %G !"A� ö, 413 K�I 4wú <�B� x

�..

2-2-2. TiO2/SiO2 Xerogel %$ Ti-Al-beta �h

Ti-Al-beta� B�� ¢%+P ¾�� SiO2-TiO2-Al2O3þB ��C:

ø �� sol-gel ;� `" àáx�.. #Í$? %� %G 0.05 M

Ï],, TEOS� C 1 # 4� � áT +ë %� %G� ö, 7��

I �8 hydrolysis56.. /& .÷ %G 0 oC? �¨56 � isopropyl

alcohol� 'f TEOT%G ×!x�I $ ¶�� öUà.. ø Í$

��? 20 wt% TEAOH%G� %A> ¢%xy ( ��56 � }

Ua cogel 110oC)*� öU 125ú�� ßh5¯, W+xy ,

TN? Ï�.. }Ua xerogel 20 wt% TEAOH%GK? ßh �

å56 � !"A� öUI B�$.(TEAOH%G/xerogel mass ratio

=3.0). �N�3 �K?P AIP ¢%x, xerogel Ï] � ö`�, g

h ¡�? ¢%xP TEAOH%G� 'yI �å5, � öUà..

408 K�I 5w ú B� � y;, R�, ßh �8 � 550oC�I =�

�8x�..

2-2-3. Dry-gel ¶·K? B�$ Ti-Al-beta

�<� H2O2(35 wt%)� %G� TBOT ö, H��I 25úÕÂ

×!xy -, ./$ 0* %G }P.. � 1bxy TEAOH%

G� NaAlO2� NaOH H��I ×!x�I 'yà.. 15ú ��

�N�3 ©�� %G 123 %G� ��( öUl, 15ú 30W

ÕÂ H��I ×!$.. /& .÷ Aaerosil 200 ��( ×!x�I

öUl, H��I 25úÕÂ ×!xy à.. }Ua ./x, ¦w$

%G ×!x�I 353 K�I T�x�.. (� Y�T Á²� ÿ�

� 2#? ��\I ×!xy l, û�( ßh+� , W�? Ï]

U à.. �3( �4$ =� <�B�A� Ù5� C ö, H��

4$ .M� ÿ��±� ßh$ W� ¦wxë 6I 7, �856

.÷ 403 K�I 4w, 448 K�I 1w <� B�x�.. B� 9�,

tT C? �¨56 � y;, R�, ßh�8 � 520oC�I 55úÕ

Â MAW�A�I =�x�..

2-2-4. Seed> %xy <�B�$ Al-free Ti-beta

:I ��8 �� x�I B�$ � �X� �� v

2> ";AT Z<� =� >�qS !"A� 1 M HNO3%G� ö,

80oC�I 245úÕÂ T�x�I ð �N�3 <bx�.. {�

y;\I pHT 6-7��ä R�$ .÷ 80oC�I 125ú ßh$ �

520oC, MA W�A�I 55úÕÂ =� �8x�.. !" %G àá

xA �\ ?@ TEAOH%G� H2O2(35 wt%) ö, ×!$ .÷

%G� TEOS H��I ×!x�I ��( öUà.. / .÷ isopropyl

alcohol� %\56 TEOT ö, ¦w$ %G �ä 25ú ��

×!$ � �� '5¯A �\ 70oC�I 45úÕÂ '� C

z!x´ T�xy à.. �AFK? }: -, ./$ ¦w$ %G

� :�I �8$ ð �N�356 �� v2 seed> ×!x�I

öUà.(4 g� v2 seed/!" %G� �j SiO2 100 g). %G !

"A� ö, 60 rpmK? ×!x�I 413 K�I 14wú B� <bx

�.. <� B� � !"A> �¨5¯, �� > y;, R�, ß

h$ � 550oC, MAW�A�I 55ú ÕÂ =� �8x�..

2-2-5. ç� W�A�I <�B�$ Al-free Ti-beta

TEAOH%G� H2O2(35 wt%) öU ×!$ .÷ TEOS H��I

×!x�I ��( óTxy hydrolysis56.. 35ú �� ×!$ .÷

isopropyl alcohol� %\56 TEOT> ��( .�x, 25ú ×!$

.÷ �� '5¯A �\ 70oC�I 2-35úÕÂ T�56.. }

Ua -, ./$ 0* %G� �� ';� ÕÂ B7� C z

!\l, HF(40 wt%) ×!x�I ��( óT$.. HF> óTx�

%GHC�I !,jHC? ��x´ � ÿ�� 2#> %xy D

�? ×!5�I ¦w$ HC? Ï�.. �� !./� 0* !,

j> !"A� �E 60 rpmK? ×!x�I 413 K�I 10wú B�x

�.. B� � !"A> �¨5¯, �� > y;$.. ��

� �� F− � R�xA �\ 80oC� �<> ¢%xy y�

Í R�x�.. ßh �8 � 550oC, MAW�A�I 55úÕÂ =�

�8x�..

2-2-6. Alkoxide grafting ¶·� �$ Ti-Al-beta

B�$ �� v2(SiO2/Al2O3=25)> ammonium nitrate(NH4NO3,

97 wt%) %\ �×�x, =� �8xy H+-�K? ÙF.. v

2� 789 �� AàK? 1.5 ÛP 5 mole% TIP> isopropyl alcohol

? 'f 100 ml %G ¹ 1 g �� > ö, H��I 35úÕÂ ×

!$ � �� > y;xy iso-propyl alcohol? R�$.. ßh, =

� �8xy 123 grafting� 5ù> àáx�..

2-2-7. Metallocene grafting ¶·� �$ Ti-Al-beta

H+-form� �� v2� 789 Aà 1.5 ÛP 5 mole%� BCTD

> chloroform� 'f.. %G 100 ml ¹ 1 g �� v2> ö

U 25ú ÕÂ H��I ×!$ � triethylamine ö, ×!x� %G

� *G H:*�I )I> `" 0*K? ��x�.. 0*

+~ � ×! J�, �� > y;$ .÷ chloroformK? 1

t R�, hexaneK? 2t R� $ � ßh, =�x�..

2-3. Characterization � Cyclohexene ��

B�$ 5ù� {� ghP CuKα K� %\ W� XRD[Rigaku

D/MAX-III(3.0 kw)]? WLx�K ,́ continuous scan mode�I 0.1 deg.

(2θ)/min� ��? 5-50 deg.(2θ) M��I N�x�.. �� XSA

µ �� CP SEM(Hitachi, X-650) %xy h¢x�.. 123

�� v2� �|, 123� WXj��I {B� H

C> [fxA �\ UV-Vis WK WL <bx�K´, Varian CARY

HWAHAK KONGHAK Vol. 40, No. 1, February, 2002

4 ��

3E double beam spectrometer> ð<56 SiO2> �àCº? 190-800 nm�

M��I N�x�..

GH ��!"� #$ �� &� á× 7OK?P ;��<=> �

��? $ cyclohexene� epoxidation !" <bx�.. !"AP �

¨AT è<� Pg Q Rq =� >�qS> ¢%x�,, S/TU

Ù> %\ ×!x�.. !"hß: 33 mmol cyclohexene(Aldrich, 98%),

10 mmol H2O2(35 wt% aqueous solution), 20 ml %�? xy 60oC�I

35úÕÂ !"x�.. %�?P CH3OH; CH3CN ¢%x�.. !

"C]: çV �� éÉA� capillaryWX(Supelco, NukolTM) è<

� Tq S?Sê/³�(ôY M600D)> ¢%xy WLx�..

3. ��

�� v2> !"C� SiO2/Al2O3 �á 25, B�� 443 K�I

5w ÕÂ B�xy �hx�.. XRD WL {; 7-9o� 21-23o 2θ¢ �I l {� ZST �2[K´, .¸ �� H: Ý\+ c�

.. �XP ��K? 400-600 nm� SA> z�, > 123 grafting

� ¢%x�.. Û$ 123 �@ v2 B�� seed? ¢%xA �xy

SiO2/Al 2O3� �á 50� � v2 {� �hx�.. Alkali � �

_P Al �� W� B�� ¢%x�,, Y�T �: !" h�; H

#FK? �: B� ��f 140oC�I 60 rpmK? ×!x�I 3wú

B�x�.. � �� {�: �<> �\ C; Ò]G 4 : 1

� ¾ëá? ^: .÷ ��W8A> %\ W8x�.. õ< v2_

� .¸ �� H: Ý\+ c�K´, �X SAP 50 nm x

` � < -~.. HNO3 %\ ð �N�35¯, R�x, ßh, =

� �8$ �� v2 gh� ��T _÷ [fx�..

3-1.��

5T <� B� ¶·K? �h$ 123 �@ v2 �� XRD {;

µ {�� SEM ¢a] Fig. 1, 2� ¨¨ �8x�.. !"( àá

n � 123�� Â��> �\ ¢%$ isopropyl alcohol: <�B�

0� BEAgh �� ¶\xV? ' �`x�.[13]. Fig. 1� Ti-Al-

beta(conv.)� XRDZS> �2aK´ ��Ff BEAgh> [fn <

-.. 123� �� 95% H� Á: {��> z�K´ .¸

�� H: Ý\+ c�.. w!FK? !" )G� alkali �

�: {��> @x5¯, 123� gh� 4� ¶\xP ÅK?

z,+~.[24-27]. 7� gh ¡�? �� Na+, K+ �@x, -P

)%� TEAOH> ¢%xy 7Ob �| {��T ��K´ 12

3� gh � 4�; cçU anatase H� TiO2 ��x�.. Cyclohexene

epoxidation !"� `� ab+ c�Pd anatase H� TiO2T ��

�f H2O2 W\> �ax, Na+, K+ � &�Yf 123 �

silanol /s� Dxë ¿<xy ��e ��$., �fg -.[28].

�| %�K? ��> R�x� �� &� hi+~K� ,õ�

TEAOH? �h$ �� &��P �4 �x�.. B��A� !"

(� �N�3 v2gh� j��> l�x´ B� ab+�I

{� �èx, 789� 123� gh � �� NUV?, %

A� W�A�I� 123 v2 B��P �N�3 !" )G� h

�� !�5 opx.. 123� �� Tn< {��T @x+,

�� <� k=x´[14], 123 �� 5 wt% H , !"

(� pHT 11 x? �²� anataseH� TiO2 ��.[20]. Fig. 2�I

� Ã Ti-Al-beta(conv.)� �XSAP 200 nm x�K´ �X)�:

g�� Täl m < -.. �A Ti-Al-beta(conv.)� <�: Table 3�

�2n Ù� Ã �� !"%G� SiO2 AàK? u 30 wt%> }

< -~.. õ< Al-beta� <� 50 wt%f Å; á×n � o ÄU

p � < -Pd Å: :�I ÓÔ$ Å�X 123 ��K? f$

ÅK? �¨�..

Ti-Al-beta(xerogel)B� 5 �N�3 óTx c`� Si/Al� �á

T 100 H � BEAghT ��+ c�.. �N�3 �K? º�

%z. isopropoxide ¢%b � B�5ú q²rK´ �N�3�

gh � �� Áë �s, �XSA� 4�.. �N�3: xerogel

Ï] � óTx`� B� 5 TEAOH %G� %\5� óTx`�� Ý

�_ �: {��(Fig. 1)> z�.. Ti-Al-beta(xerogel): <�B�

;��I xerogel û�( %\� � .�� Al ©�� 10 nm SA�

1tFf �XT ��+, "t;�� \ %G� -P )� �N�3

�� 70-80 nm� 2tF �XT ��+´ S2 ��I %G�

78u � 123 �� gh� ��+�I 2tF �X� �

è; ,�� e¸ {��T NUa., x�.[16]. �N�3 v

�T Á � B�5ú w� gh �? ]U^ < -P X8T Zì

xV? 123 gh x�I TiO2HK? å� wUy TÐ� Á

²´ B�5ú� Fz$ hz pg�.. 123; 78u� ��

Fig. 1. XRD patterns of (a) hydrothermally prepared Ti-beta(five types),(b) Al-beta(SiO2/Al2O=25) and grafted Ti-Al-beta(four types).

�� 40� �1� 2002� 2�

� �� 5

� � ��: {�� 5ú; �ü TxPd {��T 100% N

Ug� 123; 78u� ��: 50-60%��, z,+~.[16]. B

�� Ti-Al-beta(xerogel)� <� ��I� Ti-Al-beta(conv.)z. 56% ¡

H� Å � < -~.(Table 3). �X {�: w!Ff �� v2�

#Õ= $ g�� morphology z�.(Fig. 2). �XSAP 200 nm

x�K´ B�5ú që $.� �XSA> z. 4ë hzn < -

ÅK? ¢ù+~..

Ti-Al-beta(dry-gel)� B� 5 �4$ <�B� !"A� Ù5� C

ö c`�, B�(� �N�3; Na� óT _ B�$ �| U{$

�� H� �2� c�.. C <� B� hß�I steam �

K? 4%xy {��T NUP Å � < -~K´, Na� óT

_ P �� v2� {��T NU cP Y A2 12

3 �@ �� B�h�; .¸ Y .. B� �A�P 403 K�

I 965úÕÂ, k�FK? ��> �fI 448 K�I 245úÕÂ B�

x�Pd �: ��I j�T NU , Á: ��I {��è

@8� � < -.. Ti-Al-beta(dry-gel)� ��Ff XRDZSP

Fig. 1� �2�~.. �j SiO2> AàK? 35.6 wt%� Á: {� <�

}~K� dry-gel; steam�� &$ |�� ZìK? dò[17]�

�2} 43 wt%�P �4 �b.. Fig. 2� SEM¢a z� �X S

AT 50 nm x` � < -.. TS-1� �| �| 4: �� alkali �

�� !"� ÄU~8, 789� � �Xgh? 123

� �� ¶\xP ÅK? z,+~K� 4: �� Na� ��T Ti-

Al-beta(dry-gel)� B��I {��> ¶\$.� �� X g

h? 123� �� ¶\xP Å ÃP c�K´, �� !"�

@x+P ÒH� Ý\n < _~..

�� N�3 �� A �xy ð �N�3 ;� `À ��

� � v2 seed> %xy Si/Al� �áT 10,000 Hf Al-free Ti-

beta B�x�.. �N�3 � óT+ c: %A� W�A�I�

B�hß�IP Ti-beta� j� ��T NU cÏ, ð �N�

356 �� v2 seed> ¢%x� �N�3 !" Aº� _

� Ti-beta> B�n < -~.. 7O ZW�I ÓÔ$ ð �N�3 ;�

`4� Si/Al� �áT 10,000 H� ð �N�3 �� v2

Fig. 2. SEM photographs of (a) zeolite Al beta, (b) nanocrystalline zeolite beta, (c) Ti-Al-beta(conv.), (d) Ti-Al-beta(xerogel), (e) Ti-Al-beta(dry-gel), (f)Al-free Ti-beta(seed), (g) Al-free Ti-beta(F−), (h) grafted Ti-Al-beta

Table 3.Yield of Al-beta and Ti-beta in zeolite synthesized

As syn.(g solid/100 g gel) Calcination(g solid/100 g gel) Calcination(g solid/100 g SiO2)

Al-betaTi-Al-beta(conv.)Ti-Al-beta(xerogel)Ti-Al-beta(dry-gel)Al-free Ti-beta(seed)Al-free Ti-beta(F−)

8.1 g5.0 g

16 g22 g

7.3 g4.3 g

13.3 g18 g

50.2 g30 g

46.8 g35.6 g60.6 g90 g


6 ��

seed> } < -~.. /�� N�3� Z�? f\ j�� )

� 5ú =p+A �dK? 14w H� B� 5ú opx�.. Û

$ !"G� ©�� 789� Á: v�? f\ seedP !"%G� '

cK´ {��P seed� �; {�SA� �\ ô¡ �P.. Al-

free Ti-beta(seed)� XRDZSP Fig. 1; Ã ��Ff BEAgh> [

fx�,, 50 nm x� �| 4: �XT }Ur÷ � < -~.. .

¸ 123 �@ �� á\ {��T .= �: Å: B�5

ú ZìbA �d � �¨�.. B� � �� <�: SiO2

AàK? \I 60.6 wt% }~..

ð �N�356 v2 seed ¢%\ �h$ Ti-betaP �N�3K?

f$ �Y �`n < -K�, �� H#FK? Á: 7��

(Si-OH) ��? f\ À<� �ë �.. DEF ��!"� �| �

� �� Á: À<�: alkene i á�� @A !"C z. ��

H2O2 ¿< D�xë +V? !" ��> ��,, �xP ��C� #

$ DE� k=5¯P k+Ff Z!" wK6.[19]. e�I �N

�3 _, Á: =<� �º ¤P Ti-beta ç� W�A�I B

�x�.. Ã: ¶·K? B�$ ��P �� 123��

!"%G� 50% ��? �K´, 123� �# �� : 2.3 mole%

? z,+~.[20]. !" ,jH� �?Z� 54+V? <� B� ;

� 0 ×! !�5 opx�,, ç� W�A�I !"%G� pHP `

� 0�� T�A �d� � {�� 5ú opx�.. Fig. 1� �2

n Ù� Ã Al-free Ti-beta(F−)P .¸ B� ¶·� �$ ��z. {

��T Së ¡H� m < -K´ .¸ �� H� 'Ê+

c�.. <�: !")G� 100 g SiO2AàK? 90 g� �� {

� }~K´, !")G� SiO2 �W `� {�� ;�� y\ {

��T Á,, {;FK? Á: <� }: Å � < -~.. Fig. 2

� SEM ¢a�I z.5Z A� ¶·K? B�$ Ti-beta� �X)�

�� ~K� Al-free Ti-beta(F−)� �X )�: ¨a ��j )�

z�.. �X )��I� Á: {��> [fn < -~K� �X S

AT 2-5µm? �| �K´, GH!"�I [� @� T� e¸ &�

@xT �H+~..

3-2.�� grafting �� Ti-Al-beta

789� �h©�q Cº� 123 ��$ �|P ��8� �$

grafting Ñ|Ff <� B� ;��I 123 ��56 �|z.

!" �� |<x., �fg -.[29]. SiO2/Al2O3� �áT 25f H+-

form v2� GH grafting <bxy 123 ��x�.. 123:

�� Xgh� RM �Z� ��+P Å ²¤� �N�3

�� v2� �X _Z�� -P silanol/s � �N�3;

Ý«� �Y� {Bxy ��.[30]. 123 �ï¢ �� ð?ñ

�gj )ø v2� RM SA z. SV? grafting: v2 �X� _

Z�I ab `�, �H�.. Fig. 3� �2} XRDZS> �6z�

alkoxide grafting � metallocene grafting> <b$ �� gh� ��

� �� wU� c�K´ SEM¢a(Fig. 2)> z²� grafting;�

�� U{$ �X)�� > Ý\n < _~..

3-3. �� UV-Vis spectra

Fig. 3� =� � ¨¨� �h¶·K? }Ua 123 �@ ��

� v2� UV-Vis spectra> �2�~.. 123 �BC: ¢�j �

? ��xA �| �]´ ��j �? +fP �¡ �| D$d g

h �� ¢�j� �C? ��xP Ti(IV)T DEF ��!"�I �|

L &� zf., �fg -.[31]. 123�@ �� v2�

spectraP Zecchina i[32] z,$ Ù� Ã 205±3 nm, 225±5 nm, ~270nm

� ¿< ��? ��Ua.. 205±3 nm� ¿< ��P �� g

h �� xP ¢�j �� ,�� Ti X8� \¹x´ 225±5 nm

� ¿< ��P �� gh �� ,�� 123 �XT 2Ö� C

WX �: OH/sK?Z�� 8ú�-�� charge � � AfxP Å

K? z,+~.[33]. /�� Blasco i� �x� Ti-Al-beta� �| pen-

tacoordinated Ti(IV) �X? f$ ¿< ��T Fw )¸., �

Ax�.[15]. ~270 nm� 4: shoulderP ZWFK? polymerized�

hexacoordinated Ti(IV) species� Af$ ÅK? zf.. <�B��

\ 123 �� Ti-beta� �| ~330 nm�I ZST Ý\+ cP

ÅK?Z� 123� anataseH: ��x c: Å � < -~.. Al-

free Ti-beta(F−)� spectraP u 210 nm�I TS-1 � .¸ Ti-beta� á

\ �| �: ¿<��> z Pd Å: ç� W�A�I B�\I

Á: =<� �d� CWX� ¿< `� wU� cA �d ..

Grafting¶·� e� �h$ Ti-beta� �| 270-320 nmôâ� ¿<�

�P TiO2 clusters(Ti-O-Ti)� �= 8ú�> TP ��j �? �

W�� Ti� �� AfxPd[34], Å: grafting!" 123 �

�� gh �� xP Å ²¤� �� e�� 7��

Al X8�I 123 �; {Bxy NUP Å A �d .. �ð

Fig. 3. UV-Vis spectra of (a) hydrothermally prepared Ti-beta(five types),(b) grafted Ti-Al-beta(four types).

�� 40� �1� 2002� 2�

� �� 7

l)

e

?ñ �gj grafting �ï¢ � graftingz. �: ��? 123 Z

ST Õ+P Å: �X� �| 123 �X l�K? L 8ú�T �

4\ -U �� {B � 123 �8� �8� �� 2 < -

A �d .. �jFK? Ñ| <� B�� $ Ti-v2 ��P ¢�j

�� 123 X8T |Rx´ ç� W�A�I B�$ ��T Tè

ÙÚÑ$ 123� W� ��> �2�~,, grafting� �$ ��8P

�8� �C? ��xP 123 H¹� ��$., �Ua..

3-4. Ti-�� cyclohexene expoxidation � ��

Cyclohexene� epoxidation� #\ %� !" �?> Fig. 4� �2

�~.. !": Þb$ ø T �?> �\ ab�.. �? aP 0{

B M�K? �� C? epoxideT ��+, Brönsted �Y �d�

glycol, glycol ether? k�FK? !"xP �? , �? bP ��

��$ � allylic ��!" �\ 2-cyclohexene-1-ol, 2-cycloxene-1-one

K? ab+P !" .. e�I allylic ��!" o ab+� epoxide

� #$ DE�P Së �²a.. AllylicM�: MA W�A, aprotic %

�, À<� ��I @8xë ab�.[35]. y� ¶·K? B�$ Ti-beta

�� #xy ��? H2O2 ¢%$ cyclohexene� epoxidation

<bx�K´ !" 7O {;> Table 4� �8x�.. Q kg� !"

7O: MA W�A�I <b+U �jFK? allylic ��!"� {;

2-cyclohexene-1-ol, 2-cyclohexene-1-one o }Ur,, protic %�f

CH3OHz. aprotic$ CH3CN�I allylic M�� #$ DE� �i

( Á�K´ =<�� Al-free Ti-beta(F−)� �|P CH3OH %�> ¢%

\� allylic !" o ab+~.. Grafting¶·� �$ Ti-Al-beta�

IP ø T %� )ø�I allylic !" o ab+~K´, CH3CN

%�� |T �i( Á: allylicM�� #$ D��> z` � <

-~.. !" �? a�I $�5� �6z� %�? CH3CN ¢% 5

�i( �: epoxide� DE�> z�.. %�? CH3OH> ¢%n �

|� )� ��I �: epoxide DE�> z P Å: N q� �

2�P 123 X8� alcohol� ¿<K? 123 X8T Brönsted �

� �2�A �d .[36]. %�? CH3CN ¢%x� u %Af %

� WX� �\ D�$ Brönsted �Y Ze+V? �� !" 2

² epoxide� #$ DE� T56.[37]. /�� Õ5� Ti N q

%A %�� \ ZWFK? 0�� complex ��x´ complexP

epoxidation� &� k=5¯, �� xy allylic �� !"

� �a56.. Grafting ¶·� �\ àá� Ti-beta� �| <�B�

� Ti-betaz. allylicM�� #$ Á: D�� z�..

¨ �� &�: B�¶·� e� t > z�.. CH3OH� CH3CN

Õw$ %�� #\ <�B�� \ àá� �� &�: Ti-Al-

beta(conv.), Al-free Ti-beta(seed)>Ti-Al-beta(xerogel), Ti-Al-beta(dry-ge

>Al-free Ti-beta(F−)� õI? k=x�, grafting ¶·K? �h$ �

�� &�: matallocene(5%)>alkoxide(5%)>metallocene(1.5%)>alkoxid

(1.5%)� õI? k=x�.. <�B�� \ �h$ �� | &�

� t P �� 123 �� t � e¸ ÅK? zf.. Ti-Al-

beta(conv.), Al-free Ti-beta(seed)� �| !"%G; �� Ti/

(Si+Ti)áT `� ÕwbK�, Ti-Al-beta(xerogel), Ti-Al-beta(dry-gel)�

�|P B�¶·� t ? f\ 123�� .= F~..

Al-free Ti-beta(F−)P :�I ÓÔb !")G 0 123�� u

50%��Ï �� +~, �XT L d�? fxy !"

{;T !"C� [� @�� ô¡ �� ÅK? ±� �.. Grafting

¶·� �\ �h$ �� |� grafting %G 0 123�� o

Fig. 4. Mechanism of cyclohexene epoxidation.

Table 4. Catalytic reaction results of Ti-containing catalyst in the epoxidation of cyclohexene with H2O2

Ti/(Si+Ti) mol ratio in gel(×100%)

SiO2/Al2O3

mol ratio in gelTi/(Si+Ti) mol ratio in

product(×100%)*Solvent

Conversion of substrate(%)

Selectivity in product(%)

EP GLYS CHO

Ti-Al-beta(xerogel) 1.5 200 1.7 CH3CN 20.4 39.5 25.7 34.8CH3OH 17.8 3.3 88.2 8.5

Ti-Al-beta(conv.) 1.5 385 2.5 CH3CN 29.5 44.7 28.1 27.2CH3OH 26.8 3 92.1 4.9

Ti-Al-beta(dry-gel) 1.5 658 1.7 CH3CN 20.7 44.6 25.7 29.7CH3OH 18.7 3.1 90.8 6.1

Al-free Ti-beta(seed) 1.5 >10000 2.3 CH3CN 29 51.4 15.8 32.8CH3OH 26.7 1.8 84.8 13.4

Al-free Ti-beta(F−) 1.5 ∞ 0.5 CH3CN 16.4 65.4 34.6CH3OH 13 75.2 24.8

Alkoxide 1.5a 25 1.5 CH3CN 14.3 19.6 17.9 62.5CH3OH 10.1 5 78.3 16.7

Metallocene 1.5a 25 - CH3CN 18 23.9 20.1 56CH3OH 14.1 4 79.9 16.1

Alkoxide 5a 25 2.3 CH3CN 19.7 23.1 21.2 55.7CH3OH 15.2 4.9 79.9 15.2

Metallocene 5a 25 - CH3CN 21 23.3 20.1 56.6CH3OH 17.1 4.9 77.1 18

Reaction condition: catalyst 200 mg. cyclohexene 33 mmol, H2O2 10 mmol, solvent 200 ml, temperature 333 K, reaction time 3 hEP: cyclohexene oxide, GLYS: glycol and glycol ether, CHO: 2-cyclohexene-1-o1 and 2-cyclohexene-1onea: mol% of Ti in grafting solution*: XRF analysis by Korea Basic Science Institute


8 ��

nd

.:

.,

l, J.

ri-

.:

.:

C.,

e-

nd

L.,

< ¡jf v2� o: �� 123 {B+U &� ��, �ï

¢ � z. �ð?ñ 123 �gjT ¡j� 123 �gj� �8

� ��_ ,N W�n < -U &� �: Å � < -~.. <�

B�¶·; grafting¶· )ø�I CH3OHz. CH3CN %�? ¢%

b � z. �: �� &� �2�~.. %�? CH3CN ¢%n

�| epoxide� #$ DE�P �� N�3� �� k=n<

Brönsted �Y k=xA �d� Tx�.. /�� Al-free Ti-beta(seed)

� �|� y�( epoxide� ring openingK? f\ Z ��C '�

x�.. Al-free Ti-beta(seed)P seed� ²Ñ ��K? ¢�xP �N�

3; À<�� º, /8, gh � 123 X8T �Y ªK

V? \I � ��!" �� ab+P ÅK? zf.. Al-free Ti-

beta(F−)T Tè �: epoxide DE�> z P Å: �� =<�K?

f\ �� C(epoxide)� ¿< � wU� cA �d� glycol?

� k�Ff !" �=� 5¯A �d ..

4. � �

123 �@ �� v2 ��> .�$ <� B�·; ��8

grafting ¶·K? �hxy C� �� á× h¢x�.. �h$ ��

P )ø Á: {��> �2aK´, ç� W�A�I B�$ Al-free

Ti-beta(F−)T .¸ Ti-beta� á\ �i( |<$ {��> z�.. �

XSA� �| grafting·� ¡j? ¢%� Al-betaP u 400 nm, Ti-Al-beta

(conv.), Ti-Al-beta(xerogel)P <200 nm, Ti-Al-beta(dry-gel), Al-free Ti-beta

(seed)� �|P 50 nm x> z�.. Al-free Ti-beta(F−)P 2-5µm� L

{� ��x�K´, �$ �H µ SA t T �� GH !"�

� ô¡ lP Å [fx�.. UV-Vis WK WL �\, <�B

�� \ �� 123: �� gh �� ¢�j �� e�

� �X? ��x´, ZWFK? <W; {B� 6 � HC? ��x

Ï anataseH� TiO2P 'Ê+ c÷ [fx�.. !� grafting¶·

� �\ �� 123� �| _�� silanol /s � Al X8� !

"xy ��+P Å V? 4: TiO2 clusters� �= 8ú�> TP

�X��? � W�� Ti X8? f\ 270-320 nm� £: ��> z`

[fx�.. �� cyclohexene epoxidation !" &�: Õw$ %

�� #\I Ti-Al-beta(conv.), Al-free Ti-beta(seed)>Ti-Al-beta(dry-gel),

Ti-Al-beta(xerogel)>Al-free Ti-beta(F−)� õI? Áë �s, grafting¶

·� �| 123�� Á,, �ð?ñ �gj> ¢%b �T ��

� Á: Å � < -~..

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¤d: 1999�� $Î ¥a¦�� D�kgX ¢J kgá�

�xy �+~K´(KRF-99-041-E00350), �� k¢ ��¤..

��

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Synthesis, Characterization and Catalytic Properties of Titanium … · 1 HWAHAK KONGHAK Vol. 40,...

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