Temperature-programmed reduction transmission electron microscopy

Details of characterization by x-ray and electron diffraction, transmission electron microscopy and XPS are given elsewhere ( ). Temperature programmed reduction (TPR) studies using a 3%H2/N2 gas mixture, were performed on 40 mg catalyst samples in a tubular furnace (heating rate 10 C/min), using TCD and FID detection. Prior to TPR, the sample was heated in air at a specified temperature for 3h. 

The carbon fiber support and the catalysts before and after reduction were characterized with various techniques, viz. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), temperature programmed reduction (TPR), Nz-physisorption, inductively coupled plasma emission spectrometry (Vista AZ CCD simultaneous ICP-AES) and hydrogen chemisorption. 

The catalysts were characterized by temperature programmed reduction. X-ray diffiaction, transmission electron microscopy and X-ray photoelectron spectroscopy. It was observed that the activity was related to the presence of both Pd/PdO species in the bulk and at the surface of the catalyst. In the active state the PdO in the biggest particles appeared more reactive towards hydrogen than in smaller particles, suggesting a better mobility of the existing oxygen species. The relative proportion between PdO and Pd and the increase of the extent of thdr interface is probably the origin of the activity of the catalysts. 

The morphology, particle size and structure of the oxides were determined by using transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). BET surface area of the samples were measured by using Micromeritics ASAP-2000 instrument. The interaction of Ce with Mo and its effect on the nature of active oxygen species in the complex oxides were studied by using temperature-programmed reduction(TPR) and laser Raman spectroscopy (LRS). 

The catalysts were characterized by hydrogen chemisorption, transmission electron microscopy (TEM), temperature programmed reduction (TPR) and X Ray diffraction (XRD)... 

Recent advances in the preparation of ceria-based gold catalysts for hydrogen production by the WGS and PROX reactions are reviewed in this chapter. Considerable emphasis is placed on the catalyst characterization by a number of physicochemical methods X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), temperature programmed reduction (TPR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The relation between the structure, properties, and catalytic activity, as well as the nature of the active sites is also discussed. 

Silver-supported porous oxides ate promising heterogeneous catalysts for air treatment. Classical ways of preparation are incipient wet impregnation or ion exchange (in case of zeohtes) of a support with silver nitrate. Nevertheless, this precursor is known for its photosensitivity. The latter can lead to preparations that are not well controlled yet. In this contribution, the influence of the nature of the oxide support and of the thermal activation conditions towards the state and the dispersion of silver in the catalyst is investigated. Complementary characterization technic ues are used i- - Temperature Programmed Reduction (TPR) coupled with mass spectrometry (MS), UV-Visible spectroscopy (UV-Vis.) and Transmission Electron Microscopy (TEM). 

The catalysts were characterized using Light Microscopy (LM),Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Diffuse Reflection Infra Red Fourier Transform Spectroscopy (DRIFTS), and Temperature-Programmed Reduction (TPR) The effects of the preparation on the catalytic properties in the H2S oxidation were also assessed. 

---