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Calcined at different temperatures AMT / silicon dioxide catalyst with methanol monoetherification catechol reaction results are shown. The figure shows that when the calcination temperature is 533K, in the reaction 10h, the conversion of catechol and o-hydroxybenzoate ether selectivity were maintained at around 97% and 90%; the catalytic properties of the catalyst calcined 573K and 533K fired roughly equal; with the further increase in catalyst calcination temperature (623 and 773K), the conversion of catechol decreased product selectivity ortho hydroxy anisole increased slightly, and with the reaction time, the catalyst activity was significantly decreased. visible, at a relatively low firing temperature (533 and 573K) Preparation of catalyst activity and stability significantly better than the calcination of the obtained catalyst. this may be due to the nature (especially pH) catalyst surface active center after calcination has changed, thereby reducing the catalytic performance.

Life of the catalyst and regeneration methods:

To 533K calcined AMT / SiO2 as an example to further investigate the life of the catalyst and recovery method, the results are shown in Figure visible from the fresh catalyst to maintain a high stability in the first 46h, catechol conversion rate of 95% or more. As the reaction time, the catalyst activity decreased slowly, 440h when catechol conversion was 52%, continue to extend the reaction time, the catalyst activity decreased rapidly, 550h after catechol conversion rate has fallen to about 10% .AMT / stability SiO2 catalyst is lower than our previous coverage of aluminum phosphate catalyst system containing titanium, and Zn- Cl2 / Al2O3 catalyst stability is quite basic, but much better than some other supported catalyst systems such as cs / SiO2, etc. Although the AMT / silicon dioxide catalyst stability needs to be further improved, but the initial activity of the reaction and primary product selectivity higher performance reported in the literature is the best catechol and methanol vapor monoetherification one catalyst.



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