The Malaysian Journal of Analytical Sciences Vol 11 No 1 (2007): 287-293

 

 

STUDIES ON THE REACTION OF OXYGEN WITH PREOXIDISED BISMUTH MOLYBDATE CATALYST

 

Irmawati Ramli¹, Kenneth C. Waugh², Bahij H. Sakakini²

 

¹Department of Chemistry, University Putra Malaysia,

43400 Serdang, Selangor, Malaysia

²Department of Chemistry, University of Manchester,

P.O. Box 88, Manchester M60 1QD, United Kingdom

 

Abstract

Transient techniques of gas adsorption chromatography (GAC) and temperature programmed desorption (TPD) were used to study the interaction of oxygen species with preoxidised bismuth molybdate supported silica catalyst. Results showed (i) that the adsorption of oxygen atom at low adsorption temperature may results in the atom to be physically adsorbed on the surface of the activated catalyst, consistent with an activation energy of 28 kJ mol^-1 obtained from low temperature TPD, and (ii) that the amount of roughly 3.7% of the total oxygen content has been desorbed in the coverage of more than a monolayer of chemisorbed oxygen in the TPD from ambient to 1173 K of the activated catalyst.

 

Keywords : oxygen, gas adsorption chromatography, desorption, bismuth molybdate, activation energy

 

References

1.         G.W. Keulks, M.P. Rosynek,  C. Daniel, 1971, Bismuth  molybdate  catalysts.  Kinetics and  mechanism  of propylene oxidation. Ind. Eng. Chem. Prod. Res. Dev., 10(2) , 138-42 .

2.         E.G. Bithell, R.C. Doole, M.J. Goringe, M.D. Allen, M. Bowker, 1994, Crystallographic and microstructural changes in FeSbO₄ under reducing conditions, Phy. St. Sol. A: Appl. Res ., 146(1) , 461-75

3.         B. Zhou, X. Guo, and K.T. Chuang,  1993, Role of molybdenum and antimony in oxide catalysts for selective oxidation of propylene, Stud. Surf. Sc. Cat., 75, 1963-6

4.         W.M.H. Sachtler, and N.H. de Boer, 1965 Catalytic oxidation of propylene to acrolein, Proc. Intern. Congr. Catal ., 3rd. Amsterdam, 1964, 1 252-63.

5.         K. Aykan, 1968, Reduction of bismuth oxide-molybdenum trioxide catalyst during the ammoxidation of propylene in the absence of gaseous oxygen, J. Catal., 12(3), 281-90.

6.         P. Mars and D.W. van Krevelen, 1954, Oxidations carried out by means of vanadium oxide catalysts,  Chem. Eng. Sci., 3(Spec. Suppl.), 41-59 .

7.         R.K. Grasselli, J.D . Burrington, 1984, Molecular probes for the mechanism of selective oxidation and ammoxidation catalysis, Ind. Eng. Chem. Prod. Res. Dev., 23(3), 393-404.

8.         R.K. Grasselli, 1987, Factors affecting selectivity and activity of oxidation catalysts, React. Kinet. Catal. Lett., 35(1-2), 327-35 .

9.         L.D. Krenzke, G.W. Keulks,  1980,  The catalytic oxidation  of propylene.  VI. Mechanistic  studies  utilizing isotropic tracers, J. Catal., 61(2) , 316-25

10.      R.D. Wragg,  P.G. Ashmore,  J.A. Hockey, 1971, Selective oxidation of propene over bismuth  molybdate catalysts. Oxidation of propene using oxygen-18-labeled oxygen and catalyst. J. Catal ., 22(1), 49-53.

11.      Y. Moro-oka, W. Ueda, 1994, Multicomponent bismuth molybdate catalyst: a highly functionalized catalyst system for the selective oxidation of olefins. Adv. Catal., 40, 233-73.

12.      I. Ramli, K.C. Waugh, and B.H. Sakakini,  2000, Preparation  and characterisation  of bismuth  molybdate  catalysts, Malays. J. Anal. Sci. 7( 2) .

13.      K.C. Waugh, 1988, In situ study of catalysts: application in methanol synthesis and ethylene epoxidation, Appl. Catal. 43(2), 315-37.

14.      K.C.  Waugh,   1978,  Determination  of  surface  heteroenergeneity  in  catalysts  by  gas  adso rption  chromatography. Adsorption of hydrogen fluoride on chromic fluoride. J. Chromatogr. 155(1) , 83-95.