Production of Diisopropyl Ether in the Presence of Modified Heteropolyacid Catalysts Containing Titanium Oxide

The catalytic activity of titanium dioxide and its analogs modified with formoformolybdenum heteropoly acid was studied in the conversion of isopropyl alcohol. It was found that adding 10% phosphoformolybdenum heteropoly acid to titanium dioxide increased the catalyst's stability and its selectivity for diisopropyl ether by more than 1.5 times. It is suggested that the formation of diisopropyl ether in the presence of unmodified titanium dioxide occurs via the fusion mechanism, while in the presence of modified titanium dioxide, it occurs via the shock mechanism. The change in the mechanism of diisopropyl ether formation is associated with a shift in the distribution of acid-base active centers: before modification, strong and weak Lewis acid centers and Bronsted base centers are present on the surface of titanium dioxide, and the introduction of the modifier blocks strong Bronsted base centers, forming a new type—Bronsted basic centers composed of oxygen atoms.