Keggin H3PW12O40 (PW12) and Wells-Dawson H6P2W18O60 (P2W18) heteropolyacids (HPAs) are photo(catalysts) for various acid-promoted redox catalytic reactions. Their activity increases if they deposited on certain supports as metal oxides or carbon materials. Although the surface area acid-base interactions of HPAs with considered key factors performance binary material, role local structure chang...