Mechanistic Study of NOx Storage and Reduction Behavior over Pt/Alkali Metal Nitrate Nanocomposite Catalysts

点击翻译按钮获取中文摘要

Recently we have found that K-titanate nanobelts (KTN) possess highest capacity and excellent response for NOx storage reduction processes as supports. To investigate the mechanism of this process, we have employed various physico-chemical surface techniques such as XPS, XRD, EXAFS and FT-IR. We have also employed different crystalline structure TiO2 supports with various loading amounts of Pt and KNO3 to study the activity and selectivity controlling factors for NSR processes. We could conclude the following three factors were important as the NSR catalyst in the Pt-K/TiO2 system; (1) smaller Pt metal particles for rapid NO oxidation and KNO3 reduction, (2) facile migration of K cations from and back to the K-rich layers during NOx storage and reduction processes, (3) existence of a certain surface structure to maintain high dispersion of K cations.