Metal-organic frameworks-derived manganese trioxide with uniformly loaded ultrasmall platinum nanoparticles boosting benzene combustion

Catalytic Oxidation of Acetone on SmMn2O5: Effect of Acid Etching and Loading Treatment

The key of catalytic oxidation technology is to develop a stable catalyst with high activity. It is still a serious challenge to achieve high conversion efficiency of acetone with an integral catalyst at low temperature. In this study, the SmMn₂O₅ catalyst after acid etching was used as the support, and the manganese mullite composite catalyst was prepared by loading Ag and CeO₂ nanoparticles on its surface. By means of SEM, TEM, XRD, N₂-BET, XPS, EPR, H₂-TPR, O₂-TPD, NH₃-TPD, DRIFT, and other characterization methods, the related factors and mechanism analysis of acetone degradation activity of the composite catalyst were discussed. Among them, the CeO₂-SmMn₂O₅-H catalyst has the best catalytic activity at 123 and 185 °C for T₅₀ and T₁₀₀, respectively, and shows excellent water and thermal resistance and stability. In essence, the surface and lattice defects of highly exposed Mn sites were formed by acid etching, and the dispersibility of Ag and CeO₂ nanoparticles was optimized. Highly dispersed Ag and CeO₂ nanoparticles have a highly synergistic effect with the support SmMn₂O₅, and the reactive oxygen species provided by CeO₂ and the electron transfer brought by Ag further promote the decomposition of acetone on the carrier SMO-H. In the field of catalytic degradation of acetone, a new catalyst modification method of high-quality active noble metals and transition metal oxides supported by acid-etched SmMn₂O₅ has been developed.

Photo-Activated Direct Catalytic Oxidation of Gaseous Benzene with a Cu-Connected Serial Heterojunction Array of Co3 O4 /Cux O/Foam Cu Assembled via Layer upon Layer Oxidation

The foam copper (FCu) has been first used as a promising supporting material to prepare a photo-activated catalyst of Co₃ O₄ /Cu_x O/FCu, in which the fine Co₃ O₄ particles are inlayed on the Cu_x O nanowires to form a Z-type heterojunction array connected by substrate Cu. The prepared samples have been used as a photo-activated catalyst to directly decompose gaseous benzene and the optimized Co₃ O₄ /Cu_x O/FCu demonstrates a 99.5% removal efficiency and 100% mineralizing rate within 15 min in benzene concentration range from 350 to 4000 ppm under simulate solar light irradiation. To track the reactive mechanism, a series of MO_x /Cu_x O/FCu (M = Mn, Fe, Co, Ni, Cu, Zn) is prepared and a novel photo-activated direct catalytic oxidation route is proposed based on the comparative investigation of material properties. Moreover, the approach grew in situ via layer upon layer oxidation on FCu dedicates to the extra lasting reusability and the easy accessibility in the diverse situations. This work provides a novel strategy for the preparation of Cu connected series multidimensional heterojunction array and a promising application for the quick abatement of the high-leveled concentration gaseous benzene and its derivatives from the industrial discharged flow or the accident scene's leakage.