Quantification of Exchanged Copper Species in Cu‐Chabazite Zeolite using Cryogenic Probe Infrared Spectroscopy

Abstract The development of a low temperature (−160 °C) NO adsorption technique is disclosed that avoids the chemical conversion probe molecule at room temperature. observed IR peaks for Cu + (NO) 2 and 2+ species can be used to quantify amount exchanged copper in broad range samples, including wash‐coated honeycomb. Calibration curves are determined loadings up 3.99 wt% with Silica‐to‐Alumina Ratio (SAR) 16–22, quantitative agreement complementary hydrogen Temperature Programmed Reduction (H ‐TPR) results established. This methodology allows identify different Cu‐CHA, such as Z Cu(II), 1 Cu(II)OH dimers, based on their distinct signatures. In addition, perturbed T−O−T framework vibration – characterized 400 °C also complimentary method Cu(II) species.