화학공학소재연구정보센터
Applied Catalysis A: General, Vol.246, No.2, 227-235, 2003
Dehydration of 2-butanol by a sulfated zirconia/gamma-alumina mixed metal oxide catalyst inside a gas chromatograph injection port
A sulfated zirconia/gamma-alumina mixed metal oxide catalyst is prepared and utilized in the injection port of a gas chromatograph (GC) for the investigation of 2-butanol dehydration. A linear correlation (R-2 = 0.996) is found between the areas of the chromatographed butene peaks and the concentration of 2-butanol in dichloromethane standard solutions ranging from 0.003 to 3 vol.%, the injector temperature maintained at 250 degreesC. The kinetics of the alcohol dehydration are studied by varying the injector temperature. The data is found to support a pseudo-first-order reaction mechanism, with two different apparent activation energies observed over two distinct temperature ranges: 15 kJ/mol for the higher temperature range (similar to 150-325 degreesC and 46 kJ/mol for the lower temperature range (75 to similar to 150 degrees) studied. The lower apparent activation energy obtained at the higher injector temperatures is attributed to mass transport-limited kinetics, while the higher apparent activation energy barrier observed at the lower temperatures suggests that the surface alcohol dehydration reaction provides the rate-limiting step. Following exposure to stress conditions, the coke-deactivated catalyst surface is observed by scanning electron microscopy (SEM). (C) 2003 Elsevier Science B.V. All rights reserved.