Morphology-Controlled SmMn2O5 Nanocatalysts for Improved Acetone Degradation.

The SmMn₂O₅ catalyst is considered as an excellent substitute for noble-metal and transition-metal oxide catalysts due to its unique crystal structure. In order to further improve its catalytic activity for acetone degradation, SmMn₂O₅ nanocatalysts with four morphologies were synthesized by the hydrothermal method by adjusting the type of manganese source reagent, the content of mineralizing agent, and hydrothermal temperature. Among them, the SMO-NF catalyst prepared with Mn-(NO₃)₂ as the manganese source, 10 mL of NaOH, and a hydrothermal temperature of 220 °C has a special flower morphology and can achieve 100% acetone conversion at 118 °C. Because of its thin and large "petal" morphology providing active sites and oxygen vacancies, the excellent catalytic performance of the SMO-NF catalyst is an important breakthrough in the field of acetone degradation. In addition, the highly stable crystalline phase, abundant surface reactive oxygen species, and excellent reducibility of the SMO-NF catalyst also lay the foundation for its high catalytic activity, water resistance, and stability. The SMO-NS catalyst with a spherical morphology can completely degrade acetone at 136 °C, and its activity is better than that of the SMO-CP catalyst prepared by the coprecipitation method and Pt/TiO₂ catalysts. The relationship between the formation process of SmMn₂O₅ nanocatalysts with special morphology and its catalytic activity is discussed as well. The successful synthesis of the SMO-NF catalyst also opens up a way for the synthesis of the special morphology of acetone degradation nanocatalysts. [ABSTRACT FROM AUTHOR]