The Reactions of C1 Chemistry over Supported Rh/MoO<sub>3</sub> Catalysts:the Role of Promoter (MoO3)

Jin-Wook Ha

Journal of Industrial and Engineering Chemistry, Vol.3, No.2, 105-112, June, 1997

The Reactions of C1 Chemistry over Supported Rh/MoO₃ Catalysts:the Role of Promoter (MoO3)

Department of Chemical Engineering, College of Engineering, Soonchunhyang University, Asan 336-745, Korea

This study has contrasted the activity of a series of alumina and silica supported Rh/MoO₃ catalysts for reactions involving CO-H₂, CH₄-O₂,CH₄-CO at 30 atm. and temperature range of 220-350℃. Adlineation sites (kinds of active sites which are formed at the edge of Rh metallic sites and partially reduced MoO_x sites by the addition of the promoter) significantly alter the selectivity of the CO-H₂ reactions and the activation energy increased by adding the promoter in both catalyst series. On the other hand, the selectivity of CH₄-O₂ and CH₄-CO reaction is unchanged and the activity is proportional to the number of exposed Rh sites in both series. From these results, it is concluded that Rh-MoO_x sites open a new reaction pathway by parallel mechanism in CO-H₂ reaction, but CH₄-O₂ reaction appear to take place on the Rh surface. Also, adlineation sites interact with CO, but do not interact with CH₄.

[References]

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[1] Akaraki M, Ponec VA, J. Catal., 44, 439 (1976)

[2] vanderBerg F, Clezer J, Sachtler M, J. Catal., 93, 340 (1985)

[3] Driessen JM, Poels EK, Hindermann JP, Ponec V, J. Catal., 82, 26 (1983)

[4] Kip BJ, Hermans EGF, Prins R, Appl. Catal., 35, 141 (1987)

[5] Kip BJ, Hermans EGF, vanWolput JHMC, Hermans NMA, vanGrondelle J, Prins R, Appl. Catal., 35, 109 (1987)

[6] Kip BJ, "Oxygenated Hydrocarbons from CO Hydrogenation over Rh and Ir Catalysts," Ph.D. Thesis, University of Technology Eindhoven, Netherlands (1987)

[7] Kikuzono Y, Kagami S, Naito S, Onishi T, Tamaru K, Faraday Discuss. Chem. Soc., 72, 135 (1981)

[8] Vannice MA, Garten RL, J. Catal., 56, 236 (1979)

[9] Wilson TP, Kasai PH, Ellgen PC, J. Catal., 69, 193 (1981)

[10] Mori T, Masuda H, Imai H, Miyamoto A, Niizuma H, Murakami Y, J. Mol. Catal., 25, 263 (1984)

[11] Mori T, Miyamoto A, Niizuma H, Takahashi N, Fukagaya M, Hatori T, Murakami Y, J. Phys. Chem., 90, 5197 (1986)

[12] Sachtler M, Ichikawa M, J. Phys. Chem., 90, 4752 (1986)

[13] Lee G, Schuller B, Post H, Favre T, Ponec V, J. Catal., 98, 552 (1986)

[14] Stampfl SR, Chen Y, Dumesic JA, Niu C, Hill CG, J. Catal., 105, 445 (1987)