KINETIC AND TRACER STUDIES ON METHANOL CONVERSION OVER SUPPORTED PLATINUM CATALYSTS
1989
Hydrogen-deuterium exchange in methanol over Al2,O3, platinum black and alumina supported platinum catalysts have been investigated by means of mass spectrometry. The hydrogen-deuterium exchange proceeds faster over Pt/Al2O3 than either platinum black or alumina, and the rate (as well as the rate of dimethyl ether formation) increases with platinum dispersion. From the reactions CH3OH + D2, CD3OH + H2 and CD3OH + D2 the different exchange rates of the CH3 and OH groups (R1, and R2, respectively) were determined. For all catalysts studied the exchange in the OH group was two or three orders of magnitude faster than CH3 group. Exchange in the methyl group needs higher activation energy: R1/R2 ratio increases with temperature. Catalyst pretreatment has an important effect: higher activation temperature results in a higher R1/R2 ratio. A methematical method is suggested for the evaluation of exchange rates of a molecule with two different types of hydrogen and a model is given for the interpretation of measur...
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
17
References
5
Citations
NaN
KQI