Mesoporous MnCeOx solid solutions for low temperature and selective oxidation of hydrocarbons

Abstract

The development of noble-metal-free heterogeneous catalysts that can realize the aerobic oxidation of C–H bonds at low temperature is a profound challenge in the catalysis community. Here we report the synthesis of a mesoporous Mn0.5Ce0.5Ox solid solution that is highly active for the selective oxidation of hydrocarbons under mild conditions (100–120 °C). Notably, the catalytic performance achieved in the oxidation of cyclohexane to cyclohexanone/cyclohexanol (100 °C, conversion: 17.7%) is superior to those by the state-of-art commercial catalysts (140–160 °C, conversion: 3-5%). The high activity can be attributed to the formation of a Mn0.5Ce0.5Ox solid solution with an ultrahigh manganese doping concentration in the CeO2 cubic fluorite lattice, leading to maximum active surface oxygens for the activation of C–H bonds and highly reducible Mn4+ ions for the rapid migration of oxygen vacancies from the bulk to the surface.

Mesoporous metallic rhodium nanoparticles

“…Making mesoporous frameworks composed of carbon4567, metal oxides89, silica10111213, polymers141516 and metals171819 has led to enhanced performance in catalysis2021, energy conversion and storage2223, surface-enhanced Raman spectroscopy (SERS)2425 and chemical/biochemical sensing26. In particular, the application of mesoporous noble metals in the field of heterogeneous catalysis has distinct and numerous advantages in terms of performance.…”

Enhanced Catalytic Performance of Manganese and Cobalt Co–doped CeO2 Catalysts for Diesel Soot Oxidation

“…To verify the oxidation states of the manganese species, the spectra was deconvoluted into three peaks as shown in the Figure 8 (a). Accordingly, Mn 2p 3/2 peaks were located at binding energies of ∼643.8, ∼641.5 and ∼640.2 eV, which can be assigned to Mn 4+ , Mn 3+ , and Mn 2+ , respectively . While for CMC773 catalyst, the Mn 2p 3/2 peaks are shifted to slightly higher binding energies as compared to CM773 catalyst, which probably due to strong interaction between manganese and cerium oxides.…”

Atmospheric Selective Oxidation of Benzyl Alcohol Catalyzed by Pd Nanoparticles Supported on CeO2 with Various Morphologies

“…As mentioned above, ceria and its based materials are typical catalysts for multiple oxidative reactions. In particular for oxygen‐involving reactions, the catalytic activity of the materials is mainly related to the activation of oxygen molecules ,,. Regarding this point, we have performed a series of O 2 ‐TPD experiments to probe the O 2 ‐activating capability of various ceria samples.…”