Kinetics of isopropanol dehydration at a gas-solid interface over a range of bulk and supported Bronsted acid catalysts based on H3PW12O40 (HPW) Keggin-type heteropoly acid was studied in a continuous flow fixed-bed reactor in the temperature range of 55-135 degrees C and isopropanol partial pressure of 0.94-5.52 kPa. The bulk catalysts included HPW itself and its Cs acid salts CsnH3-nPW12O40 (CsnH3-nPW). The supported catalysts comprised of 15 wt.% HPW supported on SiO2, TiO2, ZrO2 and Nb2O5. Under the conditions studied, the reaction was found to be of zero order in isopropanol. The turnover rate decreased in the order HPW > Cs2.5H0.5PW approximate to Cs2HPW > HPW/SiO2 > HPW/TiO2 > HPW/Nb2O5 approximate to HPW/ ZrO2, which is in line with the acid strength of these catalysts. The true activation energies E and preexponential factors A obtained from zero-order kinetics, were found to exhibit a compensation linear relationship In A = mE + c. Moreover, the bulk and supported catalysts exhibited different compensation plots. This is suggested to be due to the different chemical structure of Bronsted acid sites in these catalysts, resulting in differing reaction mechanisms. The bulk catalysts possess strong surface H. sites located on peripheral (bridging) oxygen atoms in the Keggin unit, whereas supported HPW catalysts have weaker H+ sites probably located on oxygen atoms of support. Consequently, on the bulk catalysts, isopropanol dehydration is suggested to occur via E1 elimination pathway, whereas on the supported catalysts it might also involve a contribution of E2 elimination pathway. (C) 2012 Elsevier Inc. All rights reserved.