2D-COS of in situ μ-Raman and in situ IR spectra for structure evolution characterisation of NEP-deposited cobalt oxide catalyst during n-nonane combustion

Abstract

New catalytic systems are still in development to meet the challenge of regulations concerning the emission of volatile organic compounds (VOCs). This is because such compounds have a significant impact on air quality and some of them are toxic to the environment and human beings. The catalytic combustion process of VOCs over non-noble metal catalysts is of great interest to researchers. The high conversion parameters and cost effective preparation makes them a valuable alternative to monoliths and noble metal catalysts. In this study, the cobalt catalyst was prepared by non-equilibrium plasma deposition of organic precursor on calcined kanthal steel. Thus prepared, cobalt oxide based microstructural short-channel reactors were tested for n-nonane combustion and the catalyst surfaces were examined by in situ μ-Raman spectroscopy and in situ infrared spectroscopy. The spectra collected at various temperatures were used in generalised two-dimensional correlation analysis to establish the sequential order of spectral intensity changes and correlate the simultaneous changes in bands selectively coupled by different interaction mechanisms. The 2D synchronous and asynchronous contour maps were proved to be a valuable extension to the standard analysis of the temperature dependent 1D spectra.