Ethanol to hydrocarbons using silver substituted polyoxometalates: Physicochemical and catalytic study

Thermally stable and insoluble silver salts of 12-molybdophosphoric acid with varying amount of Ag cations were prepared. XRD results indicated the presence of single phase of AgxH3−xPMo12O40 (0 < x < 3). FTIR and Raman results indicated that Ag was incorporated in the secondary structure of Keggin ion. The catalytic conversion of ethanol increased in the order of H3PMo > Ag2PMo > Ag1PMo > Ag3PMo. Pure H3PMo is highly selective to dimethyl ether formation; in contrast AgxH3−xPMo12O40 catalysts offered better ethylene selectivity. The pyridine adsorption studies revealed that increase of Ag incorporating led to increase the Lewis acid sites.