The present work highlights for the first time that a thermal treatment of γ-Al2O3 in water at 80 °C for 24 h prior to Ag deposition (Ag/Al2O3-OH) leads to a drastic enhancement of H2-C3H6-SCR performance at low temperature. This enhancement is attributed to the higher NOx coverage on Ag/Al2O3-OH compared with that of Ag/Al2O3. The higher NOx adsorption capacity of the sample prepared from the γ-Al2O3 thermally-treated in water is proposed to result from the preferential interaction of Ag with newly-created Al2O3 anchoring sites (Al(OH)3 bayerite domains), which were not available on the untreated pristine support.