Local structure and NO adsorption/desorption property of Pd<sup>2+</sup> cations at different paired Al sites in CHA zeolite
Shunsaku Yasumura, Taihei Ueda, Hajime Ide, Katsumasa Otsubo, Chong Liu, Nao Tsunoji, Takashi Toyao, Zen Maeno, Ken‐ichi Shimizu
Abstract
infrared (IR) spectroscopy and temperature-programmed desorption (TPD) measurements. The increase in the Pd loading resulted in a shift in the NO desorption temperature toward a higher temperature regime. This phenomenon was ascribed to the increase in the proportion of less stable Pd cations, resulting in improved NO adsorption. Furthermore, the effect of Al distribution on the NO adsorption property of Pd-CHA was examined using CHA zeolites containing different proportions of paired Al sites in 6MR while maintaining similar Si/Al ratios (Si/Al = 12.0-16.5). The present study, based on a combination of theoretical and experimental techniques, shows that the NO adsorption/desorption properties over Pd-CHA can be tuned by controlling the Pd loading amount and the type of paired Al sites.