Heterogenization of 12-tungstophosphoric acid on stabilized zeolite Y.

12-tungstophosphoric acid (PW₁₂) has been supported on dealuminated zeolite Y, containing a secondary pore system with the predominant pore radii of 15 Å. The interaction between the heteropolyacid and the zeolite matrix has been studied using ²⁹Si, ²⁷Al and ³¹P MAS NMR. Distribution of two types of the Keggin anions, strongly and weakly interacting with the support, has been estimated quantitatively. Increased acidic properties of the PW₁₂/zeolite Y system were demonstrated by a change in the selectivity pattern of m-xylene transformations in the gas phase (significantly increased dealkylation and transalkylation paths at the expense of isomerization). Redox properties were evaluated in oxidation reactions with H₂O₂ in the liquid phase. It has been shown that the PW₁₂/zeolite Y catalysts can selectively oxidize a number of organic compounds at relatively low temperatures. [ABSTRACT FROM AUTHOR]