| Abstract: | The vapour phase air oxidation of 2-methylpropene to methacrolein over a copper oxide catalyst supported on pumice, modified by a continuous supply of chlorine, was investigated in an isothermal integral flow reactor at atmospheric pressure between 300 and 450 °C. The effects of several variables, weight ratio of modifier (CI) to 2-methylpropene in the feed, feed ratio of oxygen to 2-methylpropene, reaction temperature and the reciprocal of space velocity on the conversion and product distribution were determined by gas chromatography. The results indicate that the promotional effect of the modifier is mainly due to successful suppression of further oxidation of aldehyde to undesired products. Though several mechanisms were postulated, the rate of reaction was most satisfactorily correlated by a mechanism, which assumes the rate controlling step to be the surface reaction between charged adsorbed 2-methylpropene and oxygen. |
