HWAHAK KONGHAK Vol. 41, No. 4, August, 2003, pp. 445-452 · HWAHAK KONGHAK Vol. 41, No. 4, August,...

8
445 HWAHAK KONGHAK Vol. 41, No. 4, August, 2003, pp. 445-452 Co Cu-Ce/γ-Al 2 O 3 CO : (I) * ** *** **** 305-764 220 * 702-701 1370 ** 503-703 592-1 *** 305-600 100 **** 305-343 71-2 (2003 3 22 , 2003 6 16 ) Selective Oxidation of CO in Hydrogen Rich Stream over Cu-Ce/ γ-Al 2 O 3 Catalyst Doped with Co Jong Won Park , Young Woo Lee, Jin Hyeok Jeong*, Deuk Ki Lee**, Yong Ki Park*** and Wang Lai Yoon**** Department of Chemical Engineering, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764, Korea *Department of Chemical Engineering, Kyungpook National University, 1370 Sangyeok-dong, Buk-gu, Daegu 702-701, Korea **Department of Civil & Environmental Engineering, Kwangju University, 592-1 Jinwol-dong, Nam-gu, Kwangju 502-703, Korea ***Division of Advanced Technology, KRICT, 100 Jang-dong, Yuseong-gu, Daejeon 305-600, Korea ****Energy Conversion Process Research Center, KIER, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343, Korea (Received 22 March 2003; accepted 16 June 2003) γ-Al 2 O 3 Cu-Ce Co (1% CO, 1% O 2 , 60% H 2 in N 2 balance) CO . , λ(=2[O 2 ]/[CO]) . Cu-Ce , Cu-Ce(4:16 wt%) 175-220 o C 99% CO , CO 50-80% . Co Cu-Ce-Co(4.0:15.8:0.2 wt%) 150-220 o C Cu-Ce (>99% CO ) (50-94%) . (CO-/H 2 -TPR) (TPO) , Cu-Ce-Co(4.0:15.8:0.2 wt%) / , CO . Abstract - Cu-Ce/γ-Al 2 O 3 catalysts promoted with Co were prepared and tested for selective oxidation of CO in a H 2 -rich stream. The effects of promoter content, degree of excess oxygen (λ) were investigated for activity and CO selectivity while changing temperatures. Among the various Cu-Ce catalysts having different metal loadings and composition, Cu-Ce (4:16 wt%) cat- alyst showed the highest activity (>T 99 ) and selectivities (80-50%) under wide temperature range of 175-220 o C. When the Cu- Ce catalyst was further modified with 0.2 wt% Co as a promoter, the highest activity (>T 99 ) and selectivities (94-50%) was obtained over the wide temperature windows of 150-220 o C. From CO-/H 2 -TPR and TPO, it was found that by the addition of 0.2 wt% Co on Cu-Ce catalyst, oxidation-reduction activity of catalyst was improved, which resulted in the increase of cata- lytic activity and selectivity of CO oxidation in excess H 2 environment. Key words: Selective Oxidation of CO, Cu-Ce Based Catalyst, CO-/H 2 -TPR, TPO To whom correspondence should be addressed. E-mail: [email protected]

Transcript of HWAHAK KONGHAK Vol. 41, No. 4, August, 2003, pp. 445-452 · HWAHAK KONGHAK Vol. 41, No. 4, August,...

HWAHAK KONGHAK Vol. 41, No. 4, August, 2003, pp. 445-452

Co� ��� Cu-Ce/γγγγ-Al 2O3 ����� ��� � ��� CO� ��� ����:(I) �� �� � �� ��

���†������*����** �� �*** ����****

����� �����305-764 � �� �� 220

*����� �����702-701 � � ��� 1370

**����� �������503-703 �� � ��� 592-1

***����� � �� !�305-600 � �� "� 100

**** ��#$% !� � ��&� '(305-343 � �� "� 71-2

(2003) 3� 22* +,, 2003) 6� 16* -.)

Selective Oxidation of CO in Hydrogen Rich Stream over Cu-Ce/γγγγ-Al 2O3 Catalyst Doped with Co

Jong Won Park†, Young Woo Lee, Jin Hyeok Jeong*, Deuk Ki Lee**, Yong Ki Park*** and Wang Lai Yoon****

Department of Chemical Engineering, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764, Korea*Department of Chemical Engineering, Kyungpook National University, 1370 Sangyeok-dong, Buk-gu, Daegu 702-701, Korea

**Department of Civil & Environmental Engineering, Kwangju University, 592-1 Jinwol-dong, Nam-gu, Kwangju 502-703, Korea***Division of Advanced Technology, KRICT, 100 Jang-dong, Yuseong-gu, Daejeon 305-600, Korea

****Energy Conversion Process Research Center, KIER, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343, Korea(Received 22 March 2003; accepted 16 June 2003)

� �

γ-Al2O3� ��� Cu-Ce ����� ��� Co� � ��� ��� ��� ���� ��(1% CO, 1% O2, 60%

H2 in N2 balance)� ��� CO ��� ! "#�$%. �� &�, '(� ) λ(=2[O2]/[CO])! *�+,�-� � .

/� 01 23 4 ��/� ��$%. Cu-Ce ��� &� 4 5)� 01 6� 23! 78 �9 :', Cu-Ce(4:16 wt%)

��� ;< ./ =>? 175-220oC �@�� 99% @A� B< CO �� 23! C$DE, @F� CO ��/G 50-80%

HIJ%. K9 Co� �� ��9 Cu-Ce-Co(4.0:15.8:0.2 wt%) ��G 150-220oC� ;< ./ =>�� Cu-Ce ���

5�� LM N"9 � 23(>99% CO OP))' ��/(50-94%)� HIQR%. S.PT(CO-/H2-TPR) 4 S.��(TPO)

78 :', Cu-Ce-Co(4.0:15.8:0.2 wt%) ��� UN I ��� 5V ��� ��/PT W3@ �X N"�E, CO� Y9 B<

Z[\! HI]! ^ " _R%.

Abstract − Cu-Ce/γ-Al2O3 catalysts promoted with Co were prepared and tested for selective oxidation of CO in a H2-rich

stream. The effects of promoter content, degree of excess oxygen (λ) were investigated for activity and CO selectivity while

changing temperatures. Among the various Cu-Ce catalysts having different metal loadings and composition, Cu-Ce (4:16 wt%) cat-

alyst showed the highest activity (>T99) and selectivities (80-50%) under wide temperature range of 175-220oC. When the Cu-

Ce catalyst was further modified with 0.2 wt% Co as a promoter, the highest activity (>T99) and selectivities (94-50%) was

obtained over the wide temperature windows of 150-220oC. From CO-/H2-TPR and TPO, it was found that by the addition of0.2 wt% Co on Cu-Ce catalyst, oxidation-reduction activity of catalyst was improved, which resulted in the increase of cata-

lytic activity and selectivity of CO oxidation in excess H2 environment.

Key words: Selective Oxidation of CO, Cu-Ce Based Catalyst, CO-/H2-TPR, TPO

445

†To whom correspondence should be addressed.E-mail: [email protected]

446 ��������������� �����

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PI�Q �� <R� �� ST�6. 3!�%�UV +�, -�.�

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YO� Z12(autothermal reforming) [� �\ + �6[1, 2]. +X

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A0 %(HI "* 12 +��% ��� 1-2%D CO� {|�Q

��, �� !"}(Pt)\ ~�$� �} g�\ I�� x.$�� �*

� �s� �, P�.� /.: 10 ppm�.� r�$�� 06[3].

CO, �(b�� r�.� ]^��� Pd �O�, methanation YO�

�(b ��L_ [� �d� + ��w, � � �(b �� L_

(preferential oxidation, PROX)� 4� !��� ���[3-6], �S ��

�� L_�' ��� �6.

CO+1/2O2�CO2+67.6 kcal/mol (desired reaction) (1)

H2+1/2O2�H2O+58.6 kcal/mol (undesired reaction) (2)

/D � L_� CO �� L_ �g� ��#� +�D Y�� 9

.: ��b�� ��s� xy� � COD ��L_� �(b�� �

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_D �a* � ��b�� �s� +�� q�b�� L_.� �Q

�(a� ��#� �6. �r� �ZL_�D q , CO ¡a 1% �¢

�� �(a, 50%� �? £ S, �Zya��' ¤ 117oC ?a� �

6. ¥G xy �gA ¦§Q �y(200-300oC)� D =' �(a Y

O� 99% ��D CO �¨n\ ©7�� yaª(T99)� «' ¬­� �

®b�� ���6. 0t #¯M# !��Q y ¬­� 4� °¯` ±

z�� ²³´©� µ#� ¶¯ ±Z ¯`(Pt, Rh� Ru[7-12]), r·

G�¸� µ#� ¶¯ ¬­(Pt/A-zeolite[13]� Pt/mordenite[14]) YO�

¯ ±Z ¬­(Au/MnOx[15]� Au/α-Fe2O3[16]) [� P��Q¹ �6.

Y �ºb* »�, Oh� Sinkevitch[7]� :¼ ½¾D °¯` ¬­, ²

³´©� µ#$� 9¿.À��, Y � Ru� Rh� µ#� ¬­D q

  100oC� +�ÁÂÃ(900 ppm CO, 800 ppm O2, 0.85% H2 (©

Ä# N2))� �0 ��L_� CO, �D 6 L_ $Å�� �(a�

70%� �Æ6� P�.À6. Watanabe [[13]' 200oC� +�ÁÂ

�%� �0 ��L_� Pt/A-zeolite� BK0 µ#nD ²³´© ¬

­(�(a 40%)� 9Ç  +0 �(a(50-60%), P*6� P�.À

6. È0, Kahlich [[16]' +�ÁÂ�%�� É{� COD ��L_�

Au/α-Fe2O3 ¬­, 5.À�w, Au ¬­� 80oC� COD U�

Ê� 1.5 kPa K S 75%D =' �(a, ��6� P�.À6. .#l

, °¯` ¬­(Pt, Rh, Ru, Au [)� COD ���g�  +.6� <R

� �#l ���� �y� D �(a� ��, CO, 10 ppm �.�

r�.� /Ç Ë� 2� L_�� Ì�.6� �R� �6. �� ��

L_� Í� �g\ 1%� �?£ q , Ë� �¨n\ 99% �� Î\

+ ÏÐ\ D´06. ¥G ËÑ�� ��¯`D �� �Ò, Ó�$�

��¨\ ¬�$�� .� !�� �)� ���� �6[17-22].

Y �ºb* »� Avgouropoulos [[22], Liu� Flytzani-Stefanopoulos

[19, 20]� D.p Cu-Ce ¬­� KLb* Cu ��¬­� 9.: CO

�� L_ �g� +Ô Õ ?a  +.� ©7©�, Pt ±Z ¬­P6

Ö�d =' �g\ P�� ��� P�� × �6. KimA Cha[21]�

8 wt% Cu-CeO2 ¬­� 120-190oC.� CO �¨n� 99.9% ���

�, �SD �(a� 90-50% ?a, ©7�� ��� P�.À6.

�r� ceria(Ø' cerium oxide)� Z � �Ùb Ú?gA ¦§Q �

�x< � ]Í �Û� ­  =� ST� �� ¨L_ ¬­� ��

+ �#l, ÜÝM#� 4� °¯` Ø' ¯`��ÃA ÁÂ�Q �

¬­� NO 5�� �6. i�, Cu� Ce� Þß� à¬�Q B

$� CÝ.� q , ��* q � 9.: ��¨�Û� I�� X

�{A ¦§Q ��á� $�# mA, ©7�� ��� ²d¹ �6

[23]. �S, � �# ¯`D Þß0 à¬g� ��{\ ©7�� �âb

* »� , �O�yD ¨g' ceria� ã ��� Cu2+ �y>�O�

yä(Cu2+−Cu2+)>CuO clustersD å�� �6� P��� �6[23].

Y¼© L_à �� H2O� CO2� CÝ£ q , Cu-Ce ¬­D L_

�g� I�� x.�� �� � ¬­D æp TrR�� #b�6. ¥

G Cu-Ce ¬­D �g � �(g\ P6 X�$ç Ì�� ���, �

, /0 �¬­� COD è��� L_ �g�  +.6� P�� :

¼ �# ��¯`é � xy�� �g�  +0 Ã2 �êw 0�#*

Co, �dÇ ë + �6. Y �|� Co� �� ìO� q , K��

;�� �0 ­  =' �� L_�g\ ©7�� ��� ²d¹ �6

[24]. �âb* »� Cunningham [[25]� D.p å+0 Co3O4D

q , light off ya(T50)� −54oC��, γ-Al2O3� µ#� q [24]��

Ö�d ¦ �' ya* −63oC� �6� P��Q�6. í xy ���

g� �æ�  +{\ ² + ��� �¬­� D � ��g� =�

P*6. 0t �r _op� �gg�' µ#�Q 5�� �,

/0 �< bÂ0 µâ� îï Ø' ðñO% �ÒD γ-Al 2O3� 4�

5�� �6.

¥G ® !�� � γ-Al 2O3, µâ� 5.: Cu-Ce ¬­D µ

# 9n � {ò� ¥Æ Ëb�g\ Kób�� �ô �5.� .À

6. YO� L_�g X�\ /0 �¬­� Co õ�ò Ó�� ¥Æ

CO� �0 �(b �g, yaª ö< ig\ ²�P÷6. È0, CO-TPD,

CO/H2-TPR, YO� TPO ig �8\ z.: r�� ¬­éD ÃO �

Ùb igA L_ �g �*AD �øg\ ²��� .À6.

2. � �

2-1. �� ��

Aù ú {û^(excess solution impregnation)\ �.À6. 5

� ̄ ` ��â� Cu(NO3)2ü3H2O, Ce(NO3)3ü6H2O YO� Co(NO3)2ü

6H2O �ý��, γ-Al2O3(Aldrich, 150 m2/g), µâ� 5.À6.  �

��Ã2é\ .� 2ò9� X¾+(e� þÐU~D 1.3Õ)� ÿ*

� µâ, �Q �y� ¿L$Å6. �, 70oC* �H �� X)�

� �U�D +�\ r�0 � 110oC ���� 12$á BÚ è�

��$� 500oCD H� �/� .� 4$á BÚ �g.: ¬­,

r�.À6. È0, �¬­* Co� õ�� ¬­� 4¬­ ��â� B$

� õ�.: /� �W0 BK0 ]^�� ¬­, r�.À6.

2-2. �� ��

�Ê �?� ´� L_�, 5.À�� Fig. 1� 1�b* <�a

, ©7�ý6. L_�� IR furnace, z.: �Z.À��, ¬­� 100

mg(� ��, 120<dp<150µm)\ 150 mgD γ-Al2O3� �8$� Pyrex

L_�(q 6 mm, �q 4 mm)� �.: L_Z\ ��$�A B$

� L_� ya, [y�� |#.� .À6. L_Ã' 2ò|òrQ

�(MFC, Alicat Scientific)\ 5.: 1 vol% CO, 1 vol% O2, 60 vol%

H2 YO� ©Ä# N2� ��.À��, �â |ò� 100 cc/min�� K

?0 �� .� L_ �ô\ �$.À6. CO2� �¨$�� /0 CO

���� �41� �4� 2003� 8�

Co� ��� Cu-Ce/γ-Al2O3 ������ ��� CO ��� : (I) �� � ! "# $� 447

��L_� Ì�0 Ë� ��òD �0 AòD ��� H? ­1 Ó+

λ(=2[O2]/[CO])� ?D£ + �6. ¥G CO ��L_\ /0 �b

�� ¡a� λ=1��, ® �ô� � λ, 1-2.5� ��.À6.

L_à � -gà �8' �%����Y�F(HP 6890N), �.

À6. HP-Molsiv ��(Agilent5)\ �.: H2, O2 YO� N2, �O

.: Z�a �Í�(TCD)� �Í.À�, ´òD CO, �8.� /Ç

Ni-catalyst* methanizer� zA$� �;�(methanation)$� �

CarboxenTM 1006 PLOT ��\ �.: CO, CO2, CH4, §� �y

��Í�(FID)� ?ò �8.À6.

COD �(b ��L_� �Q CO �¨n(XCO), �� �ðn(XO2) �

�(a(SCO) [' ��� �� ?D.À6.

2-3. �� ��

2-3-1. �y¨�ô(CO-/H2-TPR) � �y���ô(TPO)

��¨(redox) ig\ ²�P� /Ç �y¨�ô(CO-TPR)A �

y���ô(TPO)\ +�.À6. U-type ́ �L_�, <�0 Autochem

2,910(Micromeritics Inc.)\ 5.À�� 2ò�8�(Balzers GSD

300T), �.: CO, CO2, O2 [\ o?.À6. ¬­ 0.5 g\ L_�

(�q: 10 mm)� �.�, 600oC ���/� .� 1$á �ìO0

6Ð, �� �/� .� �yM# ��$� � 1$á |#.À6. CO-TPR

D q , L_�â� 1% CO/He ÁÂ�%, 40 cc/minD |ò��

HI.p L_� ya, �y��UV 10oC/minD �y`a� 600oC

M# ��$Å�� �S, L_� Í�� D CO �ðò\ o?.À6.

TPOD q , CO-TPR� D.: K� ¨� ¬­, �y�� ��$

� � 3% O2/Ar ÁÂ�%, CO-TPRA BK0 |ò � �y`a, |

#.À�, L_� Í�� D O2 �ðò\ o?.À6. +�� D0 ¨

(H2-TPR) ig' /� �I0 BK0 �y�ô<�� Z�a�

Í�(TCD), �.: �8.À6. ¬­ 0.1 g\ L_�� �.À�,

500oC ���/� .� 1$á �ìO0 6Ð ��\ �Op 50oC

M# ��$� � 1$á |#.À6. L_�â� 10% H2/Ar �%,

30 cc/minD |ò�� �y� 20oC/minD �y`a� 500oCM# �

�$Å�� H2D �ðò\ o?.À6.

2-3-2. �y���ô(CO-TPD)

L_ÃD �� ig\ ²�P� /.: !� �´ �I0 �y

�ô<�, �.À� 2ò�8�, z.: �8.À6. "x, ¬­

0.5 g\ U-type ́ � L_�� �0 �, L_� ya, �y��UV

10oC/minD �y`a� 600oCM# 1% CO/He(40 cc/min) �/� .

� ��$� ¬­, ¨$� � �y�� ��$� 30�á |#

.À6. ��(40 cc/min) �/� .� ÃO �� Ï\ SM# ��

purge $� �, �y� 10oC/minD �y`a� 600oCM# ��b�

� ��$� CO-TPD #�\ Îý6.

3. �� �

3-1. Cu/(Cu+Ce) � ��� �� ��� CO ����

�C !�$A� D.p û�^� D.: r�� 9µ# Cu-Ce ¬­

D q , Cu : CeD 9� 2 : 8[21] Ø' 1.5 : 8.5[22]� �< ='

�g\ P�� ��� ²d¹ �6. �gg�\ �r� µâ(γ-Al 2O3)

� µ#.: 5.� q , �� � ¯`-µâáD ��%� D.:

Ëb �g� &G2 + �6. ¥G �r �op� µ#� ¬­D

Ëb �g � {ò\ $?.� /0 �e�ô� Ì�.6. Table 1' Cu

�g(' ¯` µ#ò : 10 wt% �¢)� ¥Æ L_�g �ô$A, ©7

( ��6. Cu-Ce(1:9 wt%) ¬­D q , 250oC� Ë��g(93.5%)

\ ©7�#l Cu-Ce(2:8 wt%) ¬­� 200oC� Ë��g(94.6%)\

©7�ý6. Y¼© Cu �g� Y ���� X�.� �p Ö�d L

_�g� )�{\ ë + �6. í, Cu : CeD *�9� 2 : 8K q �

Ëb �g@\ +.� �, 9� ¨�.p 3.5 : 6.5� �CD 9

µ# ¬­D Ëb 9� 9.: 6� =Ð\ ² + �6.

¥G ¬­ *�9(Cu/(Cu+Ce)), 0.2� �?0 �, Ëb µ#ò\

$?.� /.: µ#ò Ó�� ¥Æ �(b CO ��L_D �g\ �

ô �5.À6. L_ ya� ¥Æ L_�g, �� �ðò � �(a,

Fig. 2� ©7�ý6. � Y,� P� ×� �� ¯` µ#ò� 10�

25 wt%� X�{� ¥G [�¨n ya(iso-conversion temperature,

T50)� 160oC� 100oC �.� )�.�w, �� 200oC �.D x

y L_�g� ��-\ D´06. í, µ#ò X�� ¥G xy�

D CO �ò� ��b�� X�.� �� �*.� ��� .o�6.

Y¼© yaª(T99)' 20 wt%K q � 175-220oC� �< «' /

0\ P:4� �SD �(a� 80-50%�ý6. Lp� 25 wt%* q 

�� xy L_�g' ��b��  +.#l yaª(T99)� 175-200 oC�

20 wt%* q � 9.: ��b�� 1Ð\ P:¢6. �r �(b

CO ��L_ op� -�Ç ë S, BK± ¯`¬­� �Q ya

ª(T99)� ��0 g� EG´V� �s� Cu-Ce(4:16 wt%)/γ-Al2O3(�

. CuCe/A), �< bÂ0 �g � {òD ¬­� á4.: �, Kó

XCO %( )CO[ ]inlet CO[ ]outlet–

CO[ ]inlet

------------------------------------------------ 100×=

XO2%( )

O2[ ]inlet O2[ ]outlet–

O2[ ]inlet

-------------------------------------------- 100×=

SCO %( )0.5 CO[ ]inlet CO[ ]outlet–( )

O2[ ]inlet O2[ ]outlet–------------------------------------------------------------- 100×=

Fig. 1. Schematic diagram of PROX reactor system.1. Filter 5. Mixing chamber2. MFC 6. 3-way valve3. Check valve 7. Water bath4. Syringe pump

Table 1. Activity and temperature window for T>90 depending on Cu/Ce weight ratio

Catalyst max. CO conversion (%) window for T>90

Cu-Ce[0.8:9.2 wt%]/γ-Al2O3 93.6 (at 260oC) 240-280oCCu-Ce[1:9 wt%]/γ-Al2O3 93.5 (at 250oC) 220-260oCCu-Ce[2:8 wt%]/γ-Al2O3 94.6 (at 200oC) 185-230oCCu-Ce[4:6 wt%]/γ-Al2O3 92.8 (at 200oC) 190-210oCCu-Ce[8:2 wt%]/γ-Al2O3 53.5 (at 200oC) -

HWAHAK KONGHAK Vol. 41, No. 4, August, 2003

448 ��������������� �����

b* �¢ ¬­� �?.À6.

3-2. Co �� ��

!� �I0 �¢ ¬­(CuCe/A)D xy�g � �(a, P6 X

�$�� /.: �¬­� Co, 0.2, 0.5, � 1.0 wt% õ�0 ¬­D

L_g�\ 23P÷6. ® 4T� �I.# k÷#l è���, /

0 �¬­� ��g� �� :¼ �# ��¯`(Mn, Ni, Zn, Fe, Co)

\ 0.5 wt% �� õ�.: L_�ô\ +�0 $A, Co� 7 g�� 9

.: L_�g � �(a� ��b��  +0 $A, ©7�ý�� ¥

G Co, �¬­� �?.À6. Co {ò� ¥Æ CO �¨n, O2 �ð

n � CO �(a, �5.À��, Y $A, Fig. 3� ©7�ý6. K

?ò(0.2, 0.5 wt%)D Co� õ��p xy/0� COD �� �g'

X�.#l CoD {ò� 1.0 wt%�p Ö�d xy L_�g� )�.

� �\ ² +� ��� È0 CoD õ�ò� ¥G yaª(T99)� 6

5� ©76\ ² + �ý6. í, Cu-Ce-Co(4.0:15.8:0.2 wt%)/γ-Al2O3

(�. CuCeCo0.2/A), Cu-Ce-Co(3.9:15.6:0.5 wt%)/γ-Al2O3(�. CuCeCo0.5/

A) YO� Cu-Ce-Co(3.8:15.2:1.0 wt%)/γ-Al2O3(�. CuCeCo1.0/A) q

 � �Q yaª(>T99 �¢)' �� 150-220oC 7/� 170-210oC7/

YO� 200-230oC 7/À6. 0.2 wt% Co� õ�� q  ¤ 70oC ?a�

«' L_ yaª(8T99)\ �#�, 0.5 wt%� 1.0 wt% Co� õ�� q 

�� Ö�d �¢¬­* CuCe/A� 9.: 1' yaª\ ©7�ý6. �

(a op� Pp 9 �# ¬­ ð� L_ yaD X�� ¥G )�.

� q�\ P�#l, CuCeCo0.2/A ¬­D q  T99 yaª /0�

94%(150oC)�UV 50%(220oC)M# 9¿b =' �(a, PÀ6.

Fig. 2. Effect of the amount of catalysts loaded over γγγγ-Al2O3 on the COconversion, O2 consumption and the selectivity (Reaction condi-tions: 1% CO, 1% O2 and 60% H2 in N2 balance, flow rate=100ml/min, GHSV=60,000 h−1).

Fig. 3. Effect of Co addition to Cu-Ce/γγγγ-Al2O3 catalyst on the CO con-version, O2 consumption, and the selectivity (Reaction conditions:1% CO, 1% O2, 60% H2 in N2 balance, total flow rate=100 ml/min, GHSV=60,000 h−1).

���� �41� �4� 2003� 8�

Co� ��� Cu-Ce/γ-Al2O3 ������ ��� CO ��� : (I) �� � ! "# $� 449

,

,

3-3. ����[λλλλ=2O2/CO]� �� �

�r �(b ��H?D ê� $�� COD è���, /Ç b? �

�ò� HI�Q� .�, ¥G �, $?:� /0 L_�ô� ��

�6. Fig. 4� CuCeCo0.2/A ¬­� �.: ��¡a ­1 Ó+ λ(=

2O2/CO)� ¥Æ CO �� �g � �(a, ©7( ��6. λ;� X

�{� ¥G �¨n� X�{A B$� yaª(T99)� ©7©p ö�

�� �\ ² + �6. �9(λ=1)D ��� HI� q �� Ë� �

¨n� 150oC� ¤ 82% ?a�#l, λ;� 1.5� X��p(í Aù

H� HI) �' ya� D �¨n� �D 100%� �5� yaª(T99)

� ©7©� $%06. YO� λ;� 2(AùH�n 100%)� �p 150oC

� 220oC� �5� «' yaª(T99)� ©7©� �6. λ;\ Y �

��� ·O� �p yaª' �D |5.� |#.#l Ö�d �(

a� 20% ?a ��#� �s� λ=2.0\ b? �� HI¡a� <?

.À6. =�� λ=2.5* q � AòD ��� HI-��> 4 L_*

CO ��L_� 9.: UL_* H2 ��L_� ��b�� �).�

���� ST� �(a� ��#� ��� ë + �6. �r� xy/

0� � COD �g���#� +�� 9.: �� ST� CO ��

� �(b�� ��� + �6. Y¼© L_� ¥Æ ya��� KQ©

� �p COD �g� ��#� H2� 9.: ��b�� �#l +�

D �a* (frequency factor)� ��b�� ? +�� q�b�� L

_.� �Q �(a� ��#� �6[26]. ¥G +� �ðò\ Ë�

�$�� /Ç � L_ya 7/� «� λ(=2O2/CO) ;\ Ë��$

ç + �� �(a� =' ¬­� <±�Q� 06.

3-4. �� ��

3-4-1. �y¨(CO/H2-TPR) � �y��(TPO)�ô

H2 �� CÝ.� CO, �(b�� ��.� /Ç � ¬­D ��

¨ ig� ­  ��.6. ¥G Co� õ�� Cu-Ce ¬­D ��

� ¨ig\ ²�P� /.:, Cu, Ce � Co õ�� ¥Æ CO � H2

� D0 �y¨(TPR) � O2� D0 �y��(TPO) ig\ 23P÷

6. Fig. 5 � 6� ©7@ ×� ��, CO � H2� D0 Cu-Ce-Co ¬­

D ¨ ya� {|� ¬­ g�� ¥G ­  A ó�, ©7B\ ²

Fig. 4. Change in CO conversion, O2 consumption, and selectivity withλλλλ for the reaction over Cu-Ce-Co (4.0:15.8:0.2 wt%) catalyst(Reaction composition: 1% CO, 0.5-1.25% O2, 60% H2, N2 asbalance, feed rate=100 cc/min, GHSV: 60,000 h−1).

Fig. 5. CO-TPR profiles for various γγγγ-Al2O2 supported catalysts.(a) Ce[10 wt%], (b) Cu[5 wt%], (c) Cu-Ce[4:16 wt%],(d) Cu-Ce-Co[4.0:15.8:0.2 wt%], (e) Cu-Ce-Co[3.9:15.6:0.5 wt%](f) Cu-Ce-Co[3.8:15.2:1.0 wt%].

Fig. 6. H2-TPR profiles for various γγγγ-Al 2O3 supported catalysts.(a) Ce[10 wt%], (b) Cu[5 wt%], (c) Cu-Ce[4:16 wt%],(d) Cu-Ce-Co[4.0:15.8:0.2 wt%], (e) Cu-Ce-Co[3.9:15.6:0.5 wt%](f) Cu-Ce-Co[3.8:15.2:1.0 wt%].

HWAHAK KONGHAK Vol. 41, No. 4, August, 2003

450 ��������������� �����

+ �6.

CO� D0 ¨� �Q, Fig. 5� P*×� �� Cel µ#� (a)D

q  600oCM# ¨ ~�� ©7©# kÐ\ ² + ���, �� Ce

â� COD �(b ��L_� KQ©� 200oC�.� � CO� D

.: ¨�# kÐ\ D´06. È0, Cul µ#� (b)D q a xy

��L_ yaP6 =' 225oC(α~�)� 320oC(β~�)D �y /0�

CuD ¨� D0 � 1D ¨ ~�� ©76\ ² + �6. Y¼

© Ce� Cu� {C µ#� Cu-Ce �g�±¬­* (c)D q � 93oC,

150oC, 225oC � 320oC [A �� :¼ ya� ¨� KQ6\ ²

+ ���, i� ­  �' ya* 93oC� ­  D0 ¨ ~�, ©

7B\ ² + �6. í, Cu� Ce� {C µ#-�� *.: D0 ��

%\ .: CuD xy ¨ig� �� ���� ST� ¨ya�

xyE�� �� �B{\ ² +� �6. 0t, (d), (e) YO� (f)�

� �� Co� K?ò õ�� Fg�± ¬­* Cu-Ce-Co� � xy

¨ig� P6 ¦ ���Q 100oC UÑ� D ¨ ~�� ¦ ?G

\ ² + �6. È0, Cu-Ce-CoD ¬­D q  α � βD ¨ ~�

�a �y/0� ¨� KQ©� γ ~�� ©76\ ² + �6. Y

vw è� CO ��L_� KQ©� xy(200oC �.)/0� CO-

TPR $A� �Ç ¨ ~�D pb\ 9¿ �80 $A, Table 2�

P* ×� �� (d)>(e)>(c)>(f)D å � ©7H��, ���gA ¨

pbá� �øg� �Ð\ P:4ý6. �� Cu-Ce/γ-Al2O3� b?ò

D Co� µ#-�� *.: CO� D0 xy ¨ ig� P6 ¦ �

�-\ D´.�, COD ��L_�gA ßà0 ø±� �� ���

I��6.

+�� D0 ¨ig', Fig. 6D H2-TPR �ô$A� ©7@ ×�

��, ¨ya� �Q � CO� D0 ¨A A ó�, ©7�� �

�©, ¬­D µ#g�� ¥Æ /�� �Q � 9J0 q�\ ©7B

\ ² + �6. Cel� µ#� (a)D q  500oCM# ¨~�� �K

©7©# kÐ\ ² + �6. È0, Cul� µ#� (b)D q �a CO

D �(b �� L_yaP6 =' 210oC UÑ� ¨~�, ©7

B\ ² + �6. 0t, Cu� Ce� µ#� Cu-Ce ¬­* (c)D q  x

y ¨ig� ���Q 198oC(β ~�)� ¦§Q xy /0* 150oC

UV ¨� $%�Q 178oC� maximum\ L� M�ê ¨~�

(α ~�), ©7B\ ² + �6. �� 150oC-200oC ya/0� �

CO Nl �OG H2M#a ¬­, ̈ $ç + �Ð\ D´.�, Fig. 3D

�� L_ $A� ©7@ ×� ��, �� *.: H2� �0 COD �

� �(a� I�� )�.� ��� I��6. í, H2D α ¨ya

��� � Cu-Ce ¬­� H2� DÇ a ¨� � + �� ST� H2

, 4g��� .� L_à �� CÝ.� �P ¡aD CO, �(b�

� ��$�� �� Qdê ��� Ç8�6. 0t, Cu-Ce� Co� K

?ò(0.2 wt%) õ��� �p, CO-TPR $A� ��, ¦ ��D ¨y

a )�� KQ©# k�© 178oC UÑD α ¨~�D ��� ��

b�� X�{\ ² + �#l, CoD õ�ò� X�.p Ö�d α ¨

~�D ��� )�{\ ² + ���, α, β�a .�b�� 220oC

��D �y� M�ê γ ̈ ~�� ©76\ ² + �6. í, 0.2 wt%

D Co� õ�� (d)D q , 178oC, 192oC � 255oC UÑ� ̈

~�, ©7��, 0.5 wt% õ�� (e)D q , 180oC, 192oC � 220oC

UÑ� ¨~�, ©7H��, 1 wt%D Co� õ�� (f)D q ,

185oC, 213oC, � 270oC UÑ� ¨~�� ©76\ P:¢6. i

�, CoD õ�ò� X�£+Q α ¨~�� �y�� �B{\ ² +

�6. ® H2-TPR $A� Fig. 3� P� ×� �� Cu-Ce-Co ¬­D

CO �(a� 220oC ��� Cu-Ce ¬­P6 ��b�� �' �|

, ã <RÇ 4� �6. í, Cu-Ce-Co ¬­� Cu-Ce ¬­� 9.:

220oC ��D 㠨 ~� ��� X�.� ST�, �y� D CO �

(a, )�$�� ��� I��6.

ËÑ P�� !�$A� D.p, Á Cu-Ce �g�± ¬­ ��

D �(b CO ��L_$ Ce� ���� Cu ��ÃA D0 ��%

\ .: Cu ��ÃD xy ¨ �Û� ���6� P��Q �6

[19, 27, 28]. Wang [[29]' Cu, SDC� µ#$� CuO/SDC ¬­D

q  CO ��L_� �Q °¯`A �' �B\ ©7©�, �� SDC

� CÝ.� CeriaD �� � � �O ��à ±p 5�� CO,

��$ç + �� �gR� �g�� ST�G� CO-TPRA H2-TPR

�ô $A, Ñ�� <R.� �6. �� SDC� L� �� ceria ºp

D �� ${A µ#� Cu ��à 5�D D0 ��%� D.: x

y� S� ¨� KQ©� α ~�, �g.� �yD β ~� È0

xy�� �B$�� ST�� Ç8.� �6. ® !�D H2-TPR, CO-

TPR $A(Fig. 5, 6)éa �éD !�$A� ã K�.� �Ð\ ² +

�6.

H2 �� CÝ.� x¡aD CO, �(b�� �� r�.� /Ç

� COl\ ��£ + �� 200oC �.D xy/0� ¬­D ��-

¨ 5�T(redox cycle)� �.� �³Q¹� 06. ¥G ¬­D

¨ig Nl �OG ��iga ­  ��.6� £ + �6. ¬­D

��ig\ 23P� /.: TPO �ô\ �.À��, Y $A, Fig. 7

� ©7�ý6. �g�±* Cu-Ce* q  50oC UÑUV ��� ��

�Q 120oC � 250oC UÑ� Ë�;\ L� �1D �� ~�� øU

�ý6. Co� õ�� Cu-Ce-Co ¬­D q  xy �� ~�* 120oC ~

�� 5oC ?a �yE�� �B.À#l �g�±* Cu-Ce q � �

�ya�� A ó�, ©7�# k÷6. ~� pb� �Q, Co õ�ò

� ¥G ¤áVD ó�, ©7�� �Ð\ ² + �6. 0.2 wt% Co�

õ�� q  0.5 wt% õ�$Å\ SP6a A ��~� pb\ ©7�

ý6. � ¬­W� �� ~�D �� � pb\ 9¿0 $A (b)>(c)>(a)

D å � ©7H6. ® TPO $A, Fig. 5� 6D TPR $A� 9¿Ç

ë S Co� 0.2 wt% õ�� CuCeCo0.2/A ¬­� 150oC �.� D x

Table 2. The peak area of CO-TPR spectra in Fig. 5

Catalyst Area I* Area II** (Area II)/(Area I)(%)

CuCe/A 10.03 1.99 19.8CuCeCo0.2/A 11.80 2.75 23.3CuCeCo0.5/A 11.80 2.55 21.6CuCeCo1.0/A 10.87 2.05 18.9

Area I*: peak area in the temperature range of 30-600oC.Area II**: peak area in the temperature range of 30-200oC.

Fig. 7. TPO profiles for various γγγγ-Al2O3 supported catalysts.(a) Cu-Ce[4:16 wt%], (b) Cu-Ce-Co[4.0:15.8:0.2 wt%], (c) Cu-Ce-Co[3.9: 15.6:0.5 wt%].

���� �41� �4� 2003� 8�

Co� ��� Cu-Ce/γ-Al2O3 ������ ��� CO ��� : (I) �� � ! "# $� 451

n-

of

of

er-

ters,

t-

red

d-

ell

m

a-

ri-

No.

o.

y/0� D ¨�gNl �OG ���ga �< A ;\ �G\ ö

*£ + �ý6. �� �� xy ��/̈ ig� j' CuCeCo0.2/A

¬­� Fig. 3� � �� xy� D CO ��L_ �g�  +0 �

�� P� xy� D ��-̈ 5�T� �(b CO ��� $?b

0£\ {\ ² + �ý6.

¥G !� Fig. 3D �(b CO ��L_$A� Fig. 4, 5, 6D �y

¨(H2-/CO-TPR) � �y ��(TPO) �ô $A, ½ÂÇ ë S, K?

òD Co õ�� xy� S� ¨ � + �� α-~�D pb\ X�

$ç Nl �OG, �é� ¯` ��Ã�� |X� �B.: �

�, |X� Í�£ + �� �0b ��½�� CÝ.� ST�

�(b ��/̈ L_\ |a.� ��� I��6.

3-3-2. !"#$��(CO-TPD)

AòD H2� CÝ.� �/� .� �(b�� CO, �� r�.

� /Ç � £0 xy ��-̈ 5�T� �³Q¹� {' Ã��

�, L_��� L_Ã* COD ¬­ºp� D ¡a� =\+Q |

O.6. ¥G ¬­D COD �Û\ o?.� /.: CO-TPR\ +

�0 �� ¨� ¬­� �.: CO �y���ô(CO-TPD)\ +�.

: Y $A, Fig. 8� ©7�ý6.

CuCe/A ¬­� CoD õ�ò\ 0.2, 0.5 wt%� X�$�p CO-TPD

�ô\ +�0 $A, Cu-Ce �g�± ¬­ (a)D q , 280oCUÑ�

COD �� ~�, PÀ�, Co� 0.2, 0.5 wt% õ�� ¬­((b), (c))*

q  260oC� 285oCUÑ� �� ~�� �� ©7H��, CO ��

~�D �� � pb\ 9¿0 $A (b)� �< A �\ ² +� �6.

�� COD �(b �� D0 ¬­ ºp� D =' CO ¡a |#.

� /Ç � Cu-Ce �g�± P6� Co� 0.2 wt% õ�$ Ö�d ¬

­ºp� D CO ¡a ��� �� �:{��> �(b�� CO� �

�� + �� ��\ léQ ¢6� �\ ² + �ý6.

¥G ® CO-TPD $A� ! D TPR � TPO $A, ½ÂÇ ë

S, Aò�� CÝ.� H2 �/� .� �(b�� CO ��r�.�

/Ç � 6ÐA �' � �# ��\ lYÇ� {\ ² + �ý6.

i) H2� ���� 200oCP6 �' ya� a CO� D0 ¬­D

�0 ��-̈ 5�T� �³Q¹� 06.

ii) AòD H2 �/� .� ¬­ºp� D CO ¡a, =�� /.

: �(b�� CO, �.:� 06.

í, �(b CO ��, /.: �é � ��\ lY$�� ¬­� �

���, 0.2 wt% Co� µ#� CuCeCo0.2/A� �, ã lY$�� ¬

­G� �\ ö*£ + �ý6.

4. � �

Co� õ�� Cu-Ce/γ-Al2O3 ¬­� �0 ð5 12�% �� K�

�;�D �(b ��� �0 L_ �ô $A, �¤ ?O.p 6ÐA

�6.

(1) Cu/(Cu+Ce)D �g � µ#ò\ Ó�$� $A, Cu-Ce[4:16 wt%]/

γ-Al2O3 ¬­D q  99% ��D �¨n\ L� yaª(T99)' 175-220oC

�ý�� �SD �(a� 50-80%, ©7�ý6. i�, Co� õ��

Cu-Ce-Co(4.0:15.8:0.2 wt%) ¬­� Cu-Ce ¬­� 9.: yaª(T99)

� xyE�� ¤ 20oC X�{A B$� P6 =' xy �(a(50-

94%), PÀ6.

(2) λ(=2O2/CO)� X�£+Q CO �¨n' X�.#l λ� 2.5* q

 , Ö�d �(a� 20% ?a )�{\ P:4ý6.

(3) �y¨(CO-/H2-TPR) � �y��(TPO) �ô $A, CuCeCo0.2/

A ¬­� xy� α ¨~�� ©76A B$� �� � ¨~�D

Z� � pb� �< �� ST� 7 ¬­é� 9Ç ¬­D �� � ¨

L_�  +0 �\ ² + �ý6.

(4) CO-TPD �ô $A, Cu-Ce� µ#� ¬­D CO �Û� ­ 

[\ ² + ���, �� Aò�� CÝ.� H2 �/� .� ¬­º

p� D CO ¡a, X�$� xy/0� D �(b CO �� �(

a, X�$�� ��� I��6.

® !�� AÙ�WU \�#?!�� 5]D !�9 #� D.:

+��ý�� �� )5^_O6.

���

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Fig. 8. CO-TPD profiles for various γγγγ-Al2O3 supported catalysts.(a) Cu-Ce[4:16 wt%], (b) Cu-Ce-Co[4.0:15.8:0.2 wt%], (c) Cu-Ce-Co[3.9:15.6:0.5 wt%].

HWAHAK KONGHAK Vol. 41, No. 4, August, 2003

452 ��������������� �����

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B.,

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Selective Low-Temperature Oxidation of CO in H2-rich Gas over

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