Generalised two-dimensional correlation analysis of the Co, Ce, and Pd mixed oxide catalytic systems for methane combustion using in situ infrared spectroscopy

Damian K Chlebda; Przemysław J Jodłowski; Roman J Jędrzejczyk; Joanna Łojewska

doi:10.1016/j.saa.2017.11.020

Generalised two-dimensional correlation analysis of the Co, Ce, and Pd mixed oxide catalytic systems for methane combustion using in situ infrared spectroscopy

Spectrochim Acta A Mol Biomol Spectrosc. 2018 Mar 5:192:202-210. doi: 10.1016/j.saa.2017.11.020. Epub 2017 Nov 8.

Authors

Damian K Chlebda¹, Przemysław J Jodłowski², Roman J Jędrzejczyk³, Joanna Łojewska⁴

Affiliations

¹ Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland. Electronic address: damian.chlebda@uj.edu.pl.
² Faculty of Chemical Engineering and Technology, Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland.
³ Malopolska Center of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Kraków, Poland.
⁴ Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland.

PMID: 29136586
DOI: 10.1016/j.saa.2017.11.020

Abstract

The process of methane combustion over the surface of a catalyst is still not fully understood. The identification of the reaction path and the intermediates created during catalysis is crucial for understanding the transformation of methane molecules. Two-dimensional (2D) correlation spectroscopy was engaged as a tool for the quantitative analysis of a series of temperature-dependent infrared spectra registered in situ during methane combustion. The prepared samples of catalysts were based on a Co, Pd and Ce mixed oxide adsorbed on an aluminium oxide layer deposited on kanthal steel. The registered spectra were transformed into 2D synchronous and asynchronous contour maps. The sequential order of spectral intensity changes was determined, and the resolution enhancement of overlapping IR bands by 2D correlation was demonstrated. The changes in the bands' intensity and information about band position can be correlated with a specific bond, and thus, the possible process intermediates can be identified. The 2DCoS analysis proved to be a powerful tool for band enhancement and revealed the changes occurring within the analysed catalyst systems as responses to increased temperature.

Keywords: 2D correlation spectroscopy; In situ FTIR; Metal oxide; Methane combustion.