Pt/MoOx 촉매의 전이 상태 형성에 미치는 온도의 영향

김진걸; Jin Gul Kim

Journal of the Korean Industrial and Engineering Chemistry, Vol.11, No.5, 541-545, August, 2000

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Pt/MoOx 촉매의 전이 상태 형성에 미치는 온도의 영향

Effect of Temperature on Transient Kinetics of Pt/MoOx Catalyst

김진걸^†

순천향대학교 신소재화학공학부, 아산 337-745

Jin Gul Kim^†

Division of Materials and Chemical Engineering, Soonchunhyang University, Asan 337-745, Korea

E-mail:

초록

함침법에 의하여 제조된 Pt/MoO₃의 소성후에 실행된 50℃ 등온 환원 실험에서 소성온도가 증가할수록 H₂ spillover에 의하여 Pt로부터 MoO₃로 이동하여 저장되는 H₂가 증가하는 것을 측정하였다. 승온에 따른 등온환원실험에서 200℃이하에서는 반응구조식 I (H₂+Pt/MoO₃ →Pt/Mx·MoO₃)에 의하여 Pt/HxMoO₃ _(x<16) 의 형성을 측정할 수 있었고, 100℃에서 최대 H₂ 흡수 속도 및 흡수량을 나타내는 Pt/H_1.53MoO₃ 이 형성됨을 관찰하였다. 300℃이상에서는 반응구조식 II (H₂+Pt/MoO₃ →H₂O + Pt/MoOx (x 2))에 의하여 Pt/MoOx(21.95의 형성을 관찰하였다. 400℃에서 환원된 Pt/MoO₂를 시료로 하는 등온산화실험에서 반응온도가 증가함에 따라 반응구조식 III (1/2O₂+Pt/MoO_1.9251 →Pt/MoOx(x 2.5))에 의하여 Pt/MoO_x (22흡수 산화속도 및 흡수량을 보이며 Pt/MoO_2.5 가 생성되는 것을 알 수 있었다.

Isothermal reduction at 50℃ using Pt/MoO₃ made by dry impregnation showed that the H₂ uptake kinetics via H₂ spillover from Pt into MoO₃ was enhanced as calcination temperature was increased. Pt/H_xMoO₃ (x<1.6) was formed via reaction mechanism I (H₂+Pt/MoO₃ →Pt/Mx·MoO₃) during isothermal reduction experiment performed under 200℃ while highest spillover rate and amount of H₂ uptake were observed at 100℃ during formation period of Pt/H_1.53MoO₃ Pt/MoO_x(x<2) was formed via reaction mechanism II (H₂+Pt/MoO₃ →H₂O + Pt/MoOx (x 2)) of isothermal reduction from the 200℃ above up to 400℃ with highest rate of reduction kinetics. As temperature increases, Pt/MoOx (22+Pt/MoO_1.9251 →Pt/MoOx(x 2.5)) of isothermal oxidation experiment while highest rate and amount of O₂ uptake were observed at 400℃ during formation period of Pt/MoO_2.5.

Keywords:reduction;oxidation;spillover;calcination;Pt/MoOx

[References]

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Narita T, Miura H, Sugiyama K, Matsuda T, Gonzalez RD, J. Catal., 103, 492 (1987)
Bond GC, Tripathi JBP, J. Chem. Soc.-Faraday Trans., 72, 933 (1976)
Sardi A, Acta Chim. Acad. Sci. Hung, 39, 145 (1963)
Hawkins DT, Worrel WL, Metall. Trans., 271 (1970)
Fleisch TH, Mains GJ, J. Chem. Phys., 76, 780 (1982)
Benson JE, Kohn HW, Boudart M, J. Catal., 5, 307 (1966)
Boudart M, Vannice MA, Benson, J. Chem. Z Phys. Chim. Ne. Folg. Bd., 64, 171 (1969)
Tinet D, Fripiat JJ, J. Chim. Phys. Phys. Chim. Biol., 76, 867 (1979)
Boudart M, Benson MJ, Kohn H, J. Catal., 5, 307 (1966)
Bond GC, Tripathi JBP, J. Less Common. Metal., 36, 431 (1974)
Marcq JP, Poncelet G, Fripiat JJ, J. Catal., 87, 339 (1984)
Bond GC, Tripathi JBP, J. Chem. Soc.-Faraday Trans., 72, 933 (1976)
Homme GA, Boudart M, Bull. Acad. Roy. Belg. Cl. Sci., 52, 1206 (1966)
Lin X, Francois J, Lambert H, Fripiat JJ, Catal. Lett., 3, 169 (1989)
Sinfelt JM, Luccesi PJ, J. Am. Chem. Soc., 85, 3365 (1963)
El-Tanasy A, Pajonk GM, Appl. Catal., 39, 89 (1988)
Srinivas ST, Rao PK, J. Catal., 148(2), 470 (1994)
Chen B, Falconer JL, J. Catal., 144, 214 (1993)
Marcq JP, Wispennincks X, Poncelet G, Keravis D, Fripiat JJ, J. Catal., 73, 309 (1982)
Hoangvan C, Zegaoui O, Appl. Catal. A: Gen., 130(1), 89 (1995)
Kim JG, Regalbuto JR, J. Catal., 139, 175 (1993)
Bond GC, Sermon J, J. Chem. Soc.-Faraday Trans., 76, 8 (1976)
Erre R, Van Damme H, Fripiat JJ, Surf. Sci., 54, 365 (1983)
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Hegedus AJ, Sasvari K, Allgem. Chem., 293, 56 (1953)

[Referenced By]

[1] Sermon PA, Bond GC, J. Chem. Soc.-Faraday Trans., 72, 933 (1976)

[2] Narita T, Miura H, Sugiyama K, Matsuda T, Gonzalez RD, J. Catal., 103, 492 (1987)

[3] Bond GC, Tripathi JBP, J. Chem. Soc.-Faraday Trans., 72, 933 (1976)

[4] Sardi A, Acta Chim. Acad. Sci. Hung, 39, 145 (1963)

[5] Hawkins DT, Worrel WL, Metall. Trans., 271 (1970)

[6] Fleisch TH, Mains GJ, J. Chem. Phys., 76, 780 (1982)

[7] Benson JE, Kohn HW, Boudart M, J. Catal., 5, 307 (1966)

[8] Boudart M, Vannice MA, Benson, J. Chem. Z Phys. Chim. Ne. Folg. Bd., 64, 171 (1969)

[9] Tinet D, Fripiat JJ, J. Chim. Phys. Phys. Chim. Biol., 76, 867 (1979)

[10] Boudart M, Benson MJ, Kohn H, J. Catal., 5, 307 (1966)

[11] Bond GC, Tripathi JBP, J. Less Common. Metal., 36, 431 (1974)

[12] Marcq JP, Poncelet G, Fripiat JJ, J. Catal., 87, 339 (1984)

[13] Bond GC, Tripathi JBP, J. Chem. Soc.-Faraday Trans., 72, 933 (1976)

[14] Homme GA, Boudart M, Bull. Acad. Roy. Belg. Cl. Sci., 52, 1206 (1966)

[15] Lin X, Francois J, Lambert H, Fripiat JJ, Catal. Lett., 3, 169 (1989)

[16] Sinfelt JM, Luccesi PJ, J. Am. Chem. Soc., 85, 3365 (1963)

[17] El-Tanasy A, Pajonk GM, Appl. Catal., 39, 89 (1988)

[18] Srinivas ST, Rao PK, J. Catal., 148(2), 470 (1994)

[19] Chen B, Falconer JL, J. Catal., 144, 214 (1993)

[20] Marcq JP, Wispennincks X, Poncelet G, Keravis D, Fripiat JJ, J. Catal., 73, 309 (1982)

[21] Hoangvan C, Zegaoui O, Appl. Catal. A: Gen., 130(1), 89 (1995)

[22] Kim JG, Regalbuto JR, J. Catal., 139, 175 (1993)

[23] Bond GC, Sermon J, J. Chem. Soc.-Faraday Trans., 76, 8 (1976)

[24] Erre R, Van Damme H, Fripiat JJ, Surf. Sci., 54, 365 (1983)

[25] Erre R, Legacy MH, Fripiat JJ, Surf. Sci., 127, 69 (1983)

[26] Hegedus AJ, Sasvari K, Allgem. Chem., 293, 56 (1953)