Oxygen exchange in Bi2MoO6 nanosheets with different thicknesses during oxidative dehydrogenation of 1-butene

Abstract

Different from bismuth molybdate with the addition of a promoter to enhance its oxygen mobility in the oxidative dehydrogenation (ODH) reaction, Bi₂MoO₆ nanosheet catalysts with different thicknesses were controllably synthesized via a hydrothermal method and applied to ODH of 1-butene. The results revealed that the thickness of the nanosheets had a significant effect on their catalytic performance. X-ray photoelectron spectroscopy (XPS), 1-butene temperature-programmed re-oxidation (TPRO) and O₂ pulse experiments indicated that oxygen mobility and oxygen capacity were related to the nanosheet thickness. Isotopic oxygen exchange (IE) experiments were used to identify the oxygen exchange process and calculate the oxygen exchange rate. Oxygen exchange in the Bi₂MoO₆ nanosheet catalysts occurred mostly through a simple heteroexchange process and varied with the thickness of the nanosheets. The catalyst with a thickness of 35.8 nm had a suitable oxygen exchange rate and showed better activity in the reaction.