Study on reuse of metal oxide-promoted sulphated zirconia in acylation reactions

Abstract A series of sulphated zirconia samples (SZ) promoted with Al 2 O 3 , Ga 2 O 3 , and Fe 2 O 3 were synthesized by co-precipitation at constant pH and aged under reflux conditions. Structural, surface and catalytic properties of the samples were investigated using N 2 adsorption/desorption, thermal analysis, in-situ FTIR spectroscopy, TPR–MS and EGA–MS measurements. The catalytic performance of promoted SZ in anisole acylation has been investigated. Promotion by either Fe 2 O 3 or Ga 2 O 3 was found to increase the catalytic activity (yield) after recycle of catalysts with respect un-promoted sample, whereas promotion by Al 2 O 3 was observed to increase the conversion but not the yield. It is worth noting that all systems present high selectivity to the p -metoxyacetophenone product.