Multivariate and univariate analysis of infrared imaging data for high-throughput studies of NH₃decomposition and NO_xstorage and reduction catalysts

Abstract

The application of Fourier transform infrared (FTIR) spectroscopic imaging for the analysis of the reaction products from parallel reactors has been extended to the quantitative analysis of complex infrared (IR) spectra. Multivariate factor-based and univariate calibration models were developed to extract quantitative concentration information from highly overlapped IR spectra. The three multivariate factor-based models of principal component regression (PCR) and partial least squares 1 and 2 (PLS-1 and PLS-2) were employed. The effects of the number of coadded mirror scans used in the data collection and the number of factors used in the data analysis on the predictive ability of this multivariate approach were characterized. The effectiveness of these approaches is demonstrated through application to the high-throughput study of ammonia decomposition and NOx storage and reduction catalysts.

Chemical Imaging of Spatial Heterogeneities in Catalytic Solids at Different Length and Time Scales

“…Furthermore, different high-throughput screening techniques, which often use space-resolved methods, will not be covered; reference is made to articles based on IR and fluorescence microscopy. [16] 2. Yuen et al studied the spatial variation of a chemical conversion process within a fixed-bed reactor making use of in situ MRI.…”

Combinatorial and High‐Throughput Materials Science

“…Multivariate and univariate analyses of IR imaging data were also used to study NH 3 decomposition as well as NO x storage and reduction (NSR) catalysts. [243,244] Their optical set-up consisted of a spectrometer, several refractive optical elements, a gas-phase array (GPA) sampling accessory, and a mercury cadmium telluride (MCT) FPA detector with a size of 64 64 pixel. This arrangement is shown schematically in Figure 18.…”

“…Owen and Hayden used this method as a parallel optical screen for analysis of the electrochemical oxidation of methanol on Ptbased electrode arrays. [243] Combinatorial Materials Research…”

Raman and Infrared Imaging of Dynamic Polymer Systems

“…A rapid scanning FT‐IR imaging apparatus has been used for the parallel evaluation of catalysts used for propene combustion,84 carbon monoxide oxidation,85 and decomposition of ammonia 86. An ATR imaging apparatus has been used to evaluate the uptake of atmospheric moisture by a series of drug formulations in parallel,87, 88 by employing this geometry one sample surface could be exposed to a controlled atmosphere while imaging analysis was performed on the opposite of the sample.…”