AMT / SiO2 catalyst calcined at different temperatures has different degrees of AMT decomposition, resulting in different properties of the catalyst surface pH center, resulting in catalyst performance vary.

 

The result of reaction between methanol monoetherification and catechol calcined at different temperatures with AMT / SiO2 catalyst is shown in Figure 1. The figure shows that when the firing temperature is 533K, the reaction within 10h, the conversion and selectivity of catechol o-hydroxy anisole were maintained at around 97% and 90%; catalytic properties of catalyst calcined at 573K and 533K are fairly basic; with the increase of calcination temperature (623 and 773K), catechol conversion rate decreased, the selectivity of product o-hydroxy anisole increased slightly, and as the reaction time extend the activity of the catalyst decreased significantly. Obviously the activity and stability of the catalyst prepared at a relatively low firing temperature (533 and 573K) are much better than catalysts obtained at a high temperature. The properties (especially pH) of active centre on the catalyst surface changed after calcination, thereby reducing the catalytic performance.