Phosphoric Acid: A Key Role in Control of Structure and Properties of Vanadium Phosphorus Oxide Catalysts During Synthesis

The catalytic performance of vanadium phosphorus oxide (VPO) catalysts is closely related to the synthetic conditions of precursors. Herein, the role of phosphoric acid during VPO precursors synthesis process was thoroughly studied by investigating the morphology, crystal phase composition, and surface chemical property of VPO catalysts and their precursors. The H3PO4 concentration, the temperature of reaction system at the time of H3PO4 adding, and H3PO4 adding speed were optimized to prepared efficient VPO catalysts which applied in selective oxidation of n-butane to produce maleic anhydride (MA). The obtained VPO catalyst by adding 85 % H3PO4 at or above 110 degrees C with the speed of approximate 1.1 mL/min could exhibit promising catalytic performances, which are 93.8 % of n-butane conversion and 62.4 % of MA yield at 420 degrees C. Thus, this study emphasized the role of H3PO4 adding during VPO synthesis process, which is favorable to understand and fabricate the compositional, structural, and morphological properties of VPO catalysts.

Automated summary

The study thoroughly investigated the role of phosphoric acid in the synthesis of VPO catalyst precursors, optimized the synthesis conditions, and prepared efficient VPO catalysts for the selective oxidation of n-butane to produce maleic anhydride. The addition of 85% H3PO4 above 110 degrees C at a speed of approximately 1.1 mL/min resulted in promising catalytic performances, emphasizing the importance of H3PO4 in understanding and fabricating VPO catalyst properties.