Physicochemical properties of AgAlBEA and AgSiBEA zeolites were investigated by IR spectroscopy with pyridine, H2-TPR, XPS and diffuse reflectance UV–vis spectroscopy. Their catalytic properties were studied in the process of selective reduction of NO with ethanol and in the presence of hydrogen in reaction mixture. AgAlBEA catalysts show wider temperature range of NO-to-N2 conversion in the process of SCR with ethanol than AgSiBEA. Promoting H2-effect on the SCR of NO with ethanol is observed in the presence of AgAlBEA catalysts, whereas it is almost absent for AgSiBEA. A key factor for better performance of AgAlBEA than AgSiBEA is the presence of silver nanoclusters in close proximity of strong Lewis acidic sites.