Photoacoustic spectroscopy (PAS) measures a sample's absorbance spectrum directly with a controllable sampling depth and with almost no sample preparation. This technique is nondestructive, noncontact, applicable to macrosamples and microsamples, insensitive to surface morphology. In the contrary to the traditional transmission methods, PAS is carrying out the information from the surface of the measured sample. In the area of infrared PAS is a supplementary one to the other spectroscopic and classical physicochemical methods of the catalysts surface characterization. It is capable of measuring spectra of all types of solids without exposure to air or moisture. Photoacoustic spectroscopy is detecting a sample's IR spectrum by "listening" to the sound made when the sample absorbs infrared radiation. A highly sensitive microphone is used as a detector, and the spectrum is similar to absorbance spectra. One of the major advantages of PAS is its relative immunity to scattered light. Consequently, this methodology can provide absorption spectra of highly light-scattering materials such as powders (e.g. silica, alumina) or highly-absorbing materials (e.g. different type of carbonaceous adsorbents, materials, species, etc.). Several of the problems associated with the transmission techniques may be overcome utilizing photoacoustic detection (in particular, changes in the spectral region were inorganic supports are strong absorbers). Several practical and valuable examples will be presented covering various areas of catalysts investigations (catalysts preparation, adsorption, surface acidity, characterization of MCM-type materials, modified carbons, carbon deposits, etc.). Moreover, selected examples will be devoted to the comparison of data for the same studied material but obtained by the different techniques in the area of IR. Finally, there will be summarized advantages as well as the limits of the FT-IR/PAS.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/7547 must be provided.