Synthesis, Characterization and Catalytic Properties of Titanium … · 1 HWAHAK KONGHAK Vol. 40,...
Transcript of 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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����� ���� ����(2001 5� 17� �, 2001 10� 26� ��)
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 ��? $�+U -KV? SAT L @AWX
� !"�IP !"C &�Y -P �� RM �Z? [�\I ]
U^ < _KV? !" `� ab+ cP d�Y -.. e�I R
MSAT 0.7 nmf beta gh� ��� �� 123 i redox��†To whom correspondence should be addressed. E-mail: [email protected]
1
2 �������
a),
y-
,
)-
4�56 WXj ��� #$ 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 Õ hydrolysis56 � Aerosil 200 w�$ ×! �� x�I ö
Ul, 15W ՠ�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 25úÕ 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
Õ H��I ×!$.. /& .÷ Aaerosil 200 ��( ×!x�I
öUl, H��I 25úÕ ×!xy à.. }Ua ./x, ¦w$
%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
 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 45úÕ '� 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 2-35úÕ T�56.. }
Ua -, ./$ 0* %G� ��� ';� ՠB7� 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 35úÕ ×
!$ � ��� �> 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 Õ 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 Õ 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� à �� !"%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� Š� < -~.(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� h�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 245úÕ 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
HWAHAK KONGHAK Vol. 40, No. 1, February, 2002
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; à ��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� à 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
HWAHAK KONGHAK Vol. 40, No. 1, February, 2002
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 &� �: Š� < -~.. <�
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 � < -~..
�
¤d: 1999�� $Î ¥a¦��� D�kgX ¢J kgá�
�xy �+~K´(KRF-99-041-E00350), �� k¢ ��¤..
���
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