Relevance of IR Spectroscopy of Adsorbed CO for the Characterization of Heterogeneous Catalysts Containing Isolated Atoms

2021 ◽  
Author(s):  
Frederic C. Meunier
Keyword(s):  
Ir Spectroscopy ◽  
Heterogeneous Catalysts ◽  
Adsorbed Co

Characterization of the Oxidation States of Supported Gold Species by IR Spectroscopy of Adsorbed CO

2007 ◽  
Vol 79 (6) ◽  
pp. 795-806 ◽  
Author(s):  
M. Mihaylov ◽  
H. Knözinger ◽  
K. Hadjiivanov ◽  
B. C. Gates
Keyword(s):  
Ir Spectroscopy ◽  
Oxidation States ◽  
Adsorbed Co ◽  
Supported Gold

Characterization of the Oxidation States of Supported Gold Species by IR Spectroscopy of Adsorbed CO.

ChemInform ◽  
2007 ◽  
Vol 38 (36) ◽  
Author(s):  
Mihail Mihaylov ◽  
Helmut Knoezinger ◽  
Konstantin Hadjiivanov ◽  
Bruce C. Gates
Keyword(s):  
Ir Spectroscopy ◽  
Oxidation States ◽  
Adsorbed Co ◽  
Supported Gold

scholarly journals Boosting the Characterization of Heterogeneous Catalysts for H2O2 Direct Synthesis by Infrared Spectroscopy

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Maela Manzoli
Keyword(s):  
Ir Spectroscopy ◽  
Heterogeneous Catalysts ◽  
Direct Synthesis ◽  
Chemical Characterization ◽  
Ir Absorption ◽  
Spectroscopic Techniques ◽  
Catalytic Systems ◽  
Spectroscopy Studies ◽  
H2o2 Direct Synthesis

Infrared (IR) spectroscopy is among the most powerful spectroscopic techniques available for the morphological and physico-chemical characterization of catalytic systems, since it provides information on (i) the surface sites at an atomic level, (ii) the nature and structure of the surface or adsorbed species, as well as (iii) the strength of the chemical bonds and (iv) the reaction mechanism. In this review, an overview of the main contributions that have been determined, starting from IR absorption spectroscopy studies of catalytic systems for H2O2 direct synthesis, is given. Which kind of information can be extracted from IR data? IR spectroscopy detects the vibrational transitions induced in a material by interaction with an electromagnetic field in the IR range. To be IR active, a change in the dipole moment of the species must occur, according to well-defined selection rules. The discussion will be focused on the advancing research in the use of probe molecules to identify (and possibly, quantify) specific catalytic sites. The experiments that will be presented and discussed have been carried out mainly in the mid-IR frequency range, between approximately 700 and 4000 cm−1, in which most of the molecular vibrations absorb light. Some challenging possibilities of utilizing IR spectroscopy for future characterization have also been envisaged.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

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