Synthesis of Supported Catalysts by Impregnation and Calcination of Low-Temperature Polymerizable Metal-Complexes

Abstract

The low-temperature polymerizable metal complex solution has been used as an active component precursor to prepare supported (structured) catalysts by a straight-forward sequence of impregnation, drying and calcination. Two typical samples, 5 wt% Zr x Ce 1-x O 2 / Al 2 O 3 nanocomposite and structured carbon nanofiber supported Cu-CeO 2 catalyst, are prepared to explore the potential of this method in the controlled synthesis of catalysts and catalyst supports. The interaction between the active component precursor and the surface of the solid matrices during impregnation and drying is investigated by infrared spectroscopy (IR) and transmission electron microscopy (TEM), demonstrating that the in situ polymerization process is crucial for the deposition of the active component on the surface of solid matrices. The evolution of the phase transformation and the structure of the produced materials during the calcination step is studied by coupling thermal gravimetric analysis-differential thermal analysis-mass spectroscopy (TGA-DTA-MS), TEM and X-ray diffraction (XRD) measurements, indicating that higher thermal stable particles or smaller particles can be obtained with the presence of the Al 2 O 3 or structured carbon nanofibers (SCNF), respectively, after calcination. This method combines the advantages of sol-gel and impregnation, representing a promising route for preparing supported catalysts and catalyst supports. The limitations of the method are also discussed.

Tandem Hydrodeoxygenation Catalyst System for Hydrocarbons Production from Simulated Bio-oil: Effect of C–C Coupling Catalysts

“…The MoFeP active phase on supported alumina spheres was prepared by a modified Pichini method, using a sequential wetness impregnation method. Aqueous citric acid (0.4 M), an organic chelating agent, was first prepared to create an acidic environment to free the metal salts from precipitating. , A 1:1:1 molar concentration of Mo/Fe/P was added stepwise onto the 1 M citric acid solution. In the typical experiment in which 100 g of alumina spheres are used, the Mo, Fe, and P precursor weights used are 37.2, 84.8, and 23.9 g, respectively, representing 20 wt % loading of the active metal phase.…”

2D layered materials: structures, synthesis, and electrocatalytic applications

“…Some classical supporting strategies such as impregnation, alcohol reduction, and liquid phase reduction can be extended to support catalysts on 2D nanomaterials. 188,189 In addition, the stability and utilization of catalysts can be regulated by modulating the crystallinity, size, and dispersibility of catalytic active phases, as well as electronic metal-support interaction. The investigation of the electronic interactions between active species and supports needs to be stressed.…”

In Situ Scanning Transmission Electron Microscopy Calcination of Palladium Nitrate Supported on Zinc Oxide

“…Calcination treatments are central reaction steps in the synthesis of metallic particles. [5][6][7][8] During such a thermal treatment, impurities and volatile substances such as carbonates and nitrates are removed by heating the particles in an oxygen-containing atmosphere. This heat treatment may induce changes in the composition, morphology, size, distribution, and crystal structure of the nanoparticles.…”