US EPA

8708716 

Journal Article 

The mechanism of conversion of hydrocarbons on sulfated metal oxides. Part IV. Kinetics of the reaction of methylcyclopentane on sulfated zirconia 

Fǎrcaşiu, D; Li, JQ; Kogelbauer, A 

1997 

Yes 

Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 

124 

1 

67-78 

English 

10.1016/S1381-1169(97)00067-8 

The liquid-phase isomerization of methylcylopentane to cyclohexane on a sulfated zirconia catalyst (SZCH-3.5R, prepared by the controlled impregnation technique previously reported by the authors) was investigated in the stirred batch mode at four temperatures between 45 and 65°C. A kinetic analysis of the data was developed, which gave the rate constants for the isomerizations (k) and catalyst deactivation (k(d)), as well as the length of the induction period (t(O)). The activation parameters for the isomerization reaction are Δ H(+) = 16.3 kcal/mol and Δ S(+) = -30 cal/mol · deg. The rate of deactivation, k(d), is about half of the isomerization rate (k) at 45°C; at 55°C and above, the deactivation is faster than the reaction. The length of the induction period decreases with the increase in temperature and with the increasing catalyst activity. All the results are as required by the bifunctional catalysis mechanism of the reactions of saturated hydrocarbons on sulfated metal oxides (initiation by oxidation followed by acid catalysis). For a reaction in a tube without stirring the induction period is longer. Also, the rate decreases with the increase in the amount of catalyst for the same substrate to catalyst ratio, can be obtained in that case by running the reaction for several quantities of catalyst with the same substrate to catalyst ratio and extrapolating to zero catalyst bed thickness. 

Hydrocarbon conversion; Kinetics; Methylcyclopentane; Sulfated metal oxides; Zirconia