The role of Mn and Fe as promoters of sulfated zirconia (ZS) has been studied in the reaction of acrylic acid (AA) esterification by but-1-ene to see-butyl acrylate (SBA) at 343 K. The main result is that Mn and Fe did not improve the catalytic properties of sulfated zirconia as far as activity and selectivity to sec-butyl acrylate (90-95%) are concerned but strongly improved its resistance to deactivation, which makes this system attractive for substituting Amberlyst resins or sulfuric acid. The deactivation was shown not to be due to sulfated species and/or promoters leaching or to zirconia tetragonal phase transformation. It is proposed that in all cases acid sites are poisoned by the accumulation of unsaturated species primarily issue from the acrylic acid. Pyridine adsorption and n-butane isomerisation reaction at 473 K showed that the acidity of sulfated promoted zirconia was not increased by the addition of the promoters. Mn was observed by XPS to be slightly reduced during reaction while the oxidation state of the Fe was not changed. But this was shown not to be related to the deactivation process. (c) 2007 Elsevier B. V. All rights reserved.