Catalytic activity of supported silver and potassium salts of tungstophosphoric acid in dehydration of ethanol

Potassium and silver salts of tungstophosphoric acid (HPW) have been supported on silica. Two series of potassium and silver salts of tungstophosphoric acid KxH3-xPW12O40 and AgxH3-xPW12O40 where x = 1;2;3 supported on silica were prepared using incipient wetness method. In a typical synthesis, the heteropolyacid which after deposition on silica was washed with water to remove the part of heteropolyacid not bound to the support was reacted with silver or potassium salt. The vapor-phase dehydration of ethanol was employed as a test reaction. All the catalytic tests were carried out in a conventional flow type reactor, under atmospheric pressure, in the temperature range 125-500 oC. The results of these studies were used to explain the differences between the catalytic activities of heteropolysalts of potassium and silver supported on silica. (author)