Study on the preparation and n-heptane isomerization performance of MoOx-Pd/Ce-MCM-48 catalyst.

A Ce-MCM-48 molecular sieve was prepared by the hydrothermal synthesis method. Using Ce-MCM-48 as the support, a series of MoOx Pd/Ce-M catalysts were prepared by the impregnation method by introducing MoOx and Pd. XRD, N2 adsorption desorption, SEM, TEM, NH3-TPD, Py-IR, FT-IR, and ICP-MS were used to characterize the physicochemical properties. The performance of n-heptane isomerization in a micro fixed bed device was evaluated. The results showed that the synthesized Ce-MCM-48 was mesoporous, with a spherical particle morphology, a long-range ordered pore structure, weakly acidic sites on the surface, and an increase of B and L acids. The 2% MoOx-Pd/Ce-M catalyst was used for the probe reaction of n-heptane hydroisomerization; when the reduction temperature was 400 °C, the reduction time was 2 hours, the reaction temperature was 300 °C, the WHSV was 7.6 h-1, the conversion rate was 58.7%, the selectivity was 91.2%, and the maximum yield was 53.5%. The product distribution of multiple C7 isomers increased the selectivity of multi branched isoheptane. The addition of an appropriate amount of MoOx would improve the performance of n-heptane isomerization.

Metal-organic framework derived bimetallic selenide embedded in nitrogen-doped carbon hierarchical nanosphere for highly reversible sodium-ion storage.

Bimetallic selenides with various valence transitions and high theoretical capacities are extensively studied as anodes for sodium-ion-batteries (SIBs), but their huge volume changes and poor capacity retention limit their practicality. Herein, a facile and controllable strategy using a binary Ni-Co metal-organic framework (MOF) precursors followed by the selenization process, which produced a cobalt nickel selenide/N-doped carbon composite ((CoNi)Se2/NC) that maintained the hierarchical nanospheres structure. Such a distinctive structure affords both Na+ and electron diffusion pathways in the electrochemical reactions as well as high electrical conductivity, thus leading to superior electrochemical performance when the designed composite is utilized as an anode in SIBs. The resulting nanospheres-like (CoNi)Se2/NC hierarchical structure exhibits a high specific capacity of 526.8 mA h g-1 at 0.2 A/g over 100 cycles, a stable cycle life with no obvious capacities loss at 1.0 and 3.0 A/g after 500 cycles, and exceptional rate capability of 322.9 mA h g-1 at 10.0 A/g.