ALKYLATION OF CATECHOL WITH METHANOL TO GUAIACOL OVER SULPHATE-MODIFIED ZIRCONIA SOLID ACID CATALYSTS

摘要

A series of sulphate-promoted ZrO2 solid acid catalysts with different contents of SO_4~(2-)were calcined at 450°C in air for 4 h and tested for the liquid-phase alkylation of catechol to guaiacol in a fixed-bed down-flow reactor.The 5 wt.% SO_4~(2-)on ZrO2 showed the best conversion(82%)and selectivity for guaiacol(84%)at 200°C and 1 bar pressure.A smooth correlation was observed between the catalytical activity and surface acidity of sulphated zirconia.Based on our results,a surface mechanism is proposed.