An XPS and TPR study of the reduction of promoted cobalt-kieselguhr Fischer-Tropsch catalysts

Highly sulfonated polyaniline prepared via a synthetic scheme using leucoemeralding base (LEB−SPAN) has been studied using X-ray photoelectron spectroscopy (XPS). A sulfonation level (S/N ratio) as high as 0.80 ± 0.10 has been revealed in XPS analysis, agreeing well with the element chemical analysis results (∼0.78). This contrasts to an S/N ratio of 0.50 for SPAN made via the earlier reported synthetic method. The detailed S 2p and N 1s peak analyses both show that the oxidation level is ∼50%, implying a better thermal stability of emeraldine oxidation state over those of leucoemeraldine and pernigraniline oxidation states. These XPS analysis results are supported by UV−vis and FT-IR analysis results. The method of resolving 2p3/2 and 2p1/2 peaks in the S 2p spectrum is discussed.

XPS Study of Highly Sulfonated Polyaniline

XPS investigations of thermally prepared RuO2 electrodes in reductive conditions

Nonlinear least-squares curve fitting is used to analyze Ni 2p spectra obtained from various nickel-oxygen compounds and Ni/Al2O3 catalysts. Apart from NiO, which shows a characteristic discrete satellite peak 2 eV from the main 2p3/2 peak, all other spectra exhibit variable peak asymmetry assigned to multiplet splitting effects. By the use of a single extra peak to describe this asymmetry, the relative satellite/main peak intensity ratio can be used as an indication of the chemical state of nickel. Results for Ni/Al2O3 catalysts agree with reduction studies from previous work about the nature of nickel species on the surfaces of these catalysts at various nickel loadings.

Curve Fitting Analysis of ESCA Ni 2p Spectra of Nickel-Oxygen Compounds and Ni/Al2O3 Catalysts:

Valence-band and core-level x-ray photoelectron spectroscopy (XPS) of manganese and its oxides is reported and the valence-band spectra are interpreted by various calculation models. The focus of this paper is on the valence band, which shows significant differences between the oxides of manganese in the formal oxidation states II, II/III, III, IV, VI and VII. The study reports the valence band for the metal and the following oxidized forms of the metal: MnO, Mn3O4, Mn2O3, MnO2, K2MnO4 and KMnO4. The difference seen in the valence-band region makes this region appropriate for the surface analysis of manganese compounds and complements the core region, which is often complicated by broad peaks with satellite features. The valence-band region is interpreted by band structure and cluster calculations. It is shown that the differences between the observed spectra and band structure calculations for Mn3O4, Mn2O3 and MnO2 may be a result of the calculation method and not of the highly intense satellites. Copyright © 2002 John Wiley & Sons, Ltd.

Valence-band x-ray photoelectron spectroscopic studies of manganese and its oxides interpreted by cluster and band structure calculations

X-ray photoelectron spectroscopic studies of electrode surfaces using a new controlled transfer technique: Part II. Results for a molybdenum electrode and the curve fitting procedure

R.O. Ansell

Papers

X-ray photoelectron spectroscopic studies of electrode surfaces using a new controlled transfer technique: Part II. Results for a molybdenum electrode and the curve fitting procedure

X‐Ray Photoelectron Spectroscopic Studies of Tin Electrodes after Polarization in Sodium Hydroxide Solution

Quantitative use of the angular variation technique in studies of tin by X-ray photoelectron spectroscopy

An X-ray photo-electron spectroscopic study of the films on coloured stainless steel and coloured ‘Nilomag’ alloy 771

X-ray photoelectron spectroscopic studies of electrode surfaces using a new controlled transfer technique