Mixed salts of silver and ammonium derivatives of molybdovanadophosphoric acid to improve the catalytic performance in the oxidation of starch

Abstract Mixed salts of silver and ammonium derivatives Ag x (NH4) 5− x PMo 10 V 2 O 40 ( x  = 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0) were designed and synthesized through ion exchange along with precipitation. Different molar ratio of Ag + to NH 4 + resulted in different surface areas, which could give different oxidative catalytic activity in oxidation of starch. Among all molybdovanadophosphoric salts, Ag 3.5 (NH 4 ) 1.5 PMo 10 V 2 O 40 was found to be the most active catalyst in starch oxidation with the highest degree of substitution (DS = 0.62 mol/100 g). And Ag 3.5 (NH 4 ) 1.5 PMo 10 V 2 O 40 could be reused several times without significant loss of its catalytic activity.