Efficient NO_x abatement by passive adsorption over a Pd-SAPO-34 catalyst prepared by solid-state ion exchange  

作　　者：Linhui Liu Wuwan Xiong Mingli Fu Junliang Wu Zhenguo Li Daiqi Ye Peirong Chen 

机构地区：[1]National Engineering Laboratory for VOCs Pollution Control Technology and Equipment,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control,School of Environment and Energy,South China University of Technology,Guangzhou 510006,China [2]National Engineering Laboratory for Mobile Source Emission Control Technology,China Automotive Technology&Research Center Co.,Ltd.,Tianjin 300300,China

出　　处：《Chinese Chemical Letters》2024年第4期210-213,共4页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.21976058);the Natural Science Foundation of Guangdong Province (No.2023A1515011682);the Fundamental Research Funds for the Central Universities (No.2022ZYGXZR018);the National Engineering Laboratory for Mobile Source Emission Control Technology (No.NELMS2020A10);the funding from the Pearl River Talent Recruitment Program of Guangdong Province (No.2019QN01L170);the Innovation & Entrepreneurship Talent Program of Shaoguan City。

摘　　要：Palladium-exchanged chabazite(Pd-CHA) zeolites as passive NO_x adsorbers(PNAs) enable efficient purification of nitrogen oxides(NO_x) in cold-start diesel exhausts. Their commercial application, however,is limited by the lack of facile preparation method. Here, high-performance CHA-type Pd-SAPO-34 zeolite was synthesized by a modified solid-state ion exchange(SSIE) method using PdO as Pd precursor,and demonstrated superior PNA performance as compared to Pd-SAPO-34 prepared by conventional wetchemistry strategies. Structural characterization using Raman spectroscopy and X-ray diffraction revealed that the SSIE method avoided water-induced damage to the zeolite framework during Pd loading. Mechanistic investigations on the SSIE process by in situ infrared spectroscopy and X-ray photoelectron spectroscopy disclosed that, while PdO precursor was mainly converted to Pd^(2+) cations coordinated to the zeolite framework by consuming the-OH groups of the zeolite, a portion of PdO could also undergo thermal decomposition to form highly dispersed Pd~0 clusters in the pore channels. This simplified and scalable SSIE method paves a new way for the cost-effective synthesis of defect-free high-performance Pd-SAPO-34 zeolites as PNA catalysts.

关 键 词：Pd-SAPO-34 Passive NO_x adsorber Pd loading Solid-state ion exchange Pd transformation 

分 类 号：O643.36[理学—物理化学] X701[理学—化学]