Effect of Cs content on CsxH5−xPMo10V2O40 properties and oxidative catalytic activity on starch oxidation by H2O2

Abstract

A series of cesium substituted molybovanadophosphric acids, Cs_xH_5−xPMo₁₀V₂O₄₀ (x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 5.0), were synthesized by controlling the ratio of Cs⁺ to PMo₁₀V₂O₄₀⁵⁻. These complexes were characterized by ICP-AES, FT-IR, XRD, nitrogen physisorption, SEM and H_o measurement. The surface area and acid strength could be adjusted by changing the molar ratio of Cs to H. The highest surface areas were obtained when x = 5 and the highest acidity when x = 0. The catalytic activity of these compounds was evaluated for the oxidation of starch by H₂O₂, showing that the Brønsted acidity and surface area might influence the oxidation activity. Among all the prepared catalysts, Cs₃H₂PMo₁₀V₂O₄₀ exhibited the best catalytic performance with a carboxylic content of 0.59 mol per 100 g, which could be attributed to the synergy of its Brønsted acidity and surface area. This solid catalyst could be reused at least 6 times without significant loss of performance.