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Abstract

Reliable procedures for controlled synthesis of phase-pure MoVTeNb mixed oxides with “M1” structure and tunable crystal dimensions have been developed to study the structure sensitivity of selective oxidation of propane to acrylic acid. A series of M1 powdered catalysts was successfully prepared on a gram scale via a hydrothermal-based route, purification of biphasic M1/M2 oxide systems and an innovative approach utilizing superheated-water vapor treatment of calcined precursors. The influence of the preparation technique on the particle morphology and size is discussed. Detailed experimental studies highlight that the as-derived catalytic materials are indeed phase-pure and compositionally uniform MoVTeNb oxide M1 powders, composed of single-crystalline and structural defect-free crystals growing along the c-axis. The morphologically different catalysts were studied in selective oxidation of propane to acrylic acid revealing that active sites appear on the entire M1 surface and illustrating the high sensitivity of catalyst performance on the catalyst synthesis method.