Researchers have made great progress in understanding the complex interaction between sulfur dioxide (therefore2) And Copy-CHA catalyst, which is important for the selective catalytic reduction (SCR) of nitrogen oxides (nonex) Ammonia (NH3) In the diesel exhaust system. This study was led by Dr. Ton Janssens from Umicore Denmark APS from European synchronous radiation facilities and Dr. Kirill Lomachenko from European synchronous radiation facilities. Reza Abasabadi, Dr. Elisa Borfecchia, Professor Silvia Bordiga and Professor Gloria Berlier of Turin University; and Umicore Ag & Co. Dr. Fei Wen. It clarifies So’s mechanism2 Use the CU-CHA catalyst poisoning in the high-end X-ray absorption spectrum (XAS). The study was published in the magazine of Chemistry Science.
CU-CHA catalysts are favored in the diesel exhaust system because they have high activity at low temperature and stability at high temperatures. However, their performance seriously hinders the existence of SO2Need to use ultra -low sulfur diesel fuel. The first challenge is due to the discontinuation of the CU-CHA catalyst at low temperature2 Exposure. This research aims to clarify the reaction mechanism involved in SO2 Effect and its impact on the performance of catalysts.
Researchers use X-ray absorption spectrum (XAS) on CU K-Edge and S K-Edge, as well as X-ray launch spectrum (XES) to study the interaction between So2 And CU-CHA catalyst with different copper content. They discovered2 and [Cu2II(NH3)4O2]2+ The complex formed during the NH period3-SCR cycle leads to the formation of CUI Species and sulfuric acid -based CUII complexes are accumulated in the burpester hole. Studies have found SO2 The absorption mechanism is consistent between catalysts with different CU loads.
An important discovery is to increase2 Absorbing in the absence of oxygen, this helps oxidize the oxidation of the oxidationI Species enter [Cu2II(NH3)4O2]2+ Complex, so that it can be used for further reactions2Essence X -ray adsorption material quantity (XAQ) and SO temperature filling prove this2 (so2-TPD).
Dr. Lomachenko pointed out: “Our research shows that the intake of sulfur is actually promoted by the oxidation of the CUI species. This is an important insight to reduce the influence of SO.2Essence “
The research team combines a combination of multi-curve resolution and combination of combination (LCF) to analyze the experimental spectrum with a combination of a combination of multi-curve resolution and minimal two-multiplication (MCR-ALS) method and linear combination (LCF). They have determined the formation of vulcanization ingredients, mainly existing, so42– Species, in the CU-CHA catalyst exposed to SO2Essence SK edge XANES and Kαxes spectrals confirm the oxidation state of sulfur and its local environment, and align with the presence of sulfate substances.
Dr. Janssens emphasized: “Understand the interaction between SO2 CU-CHA catalyst is very important for developing more effective SCR catalysts. This catalyst can withstand sulfur poisoning to ensure the long-term survivability of the diesel exhaust system. “
The discovery of this study provides valuable insights on the SO mechanism2 Poisoning and paving the development of the development of more robust CU-CHA catalysts, the catalyst can maintain high activity when the existence of sulfur compounds. Dr. Janssens, Dr. Lomachenko and his colleagues plan to focus future research on optimizing catalyst composition and response conditions to further enhance its resistance to this resistance2 Disable.
Journal reference
Molokova, AY, ABASABADI, RK, BORFECCHIA, E.2 Use NH CU-CHA catalyst3-SCR absorbs spectral method through X -ray. Chemical science, 14,11521–11531. Doi: https: //doi.org/10.1039/d3SC03924B
About the author
Anastasia molokova It is a postdoctoral researcher who specializes in chemical application X -ray absorption spectrum (XAS). Her BM23 and ID24 XAS beam lines of Synchronous Radiation Facilities (ESRF) in France work. Anastasia completed a PhD. In 2023, under the joint supervision of Professor Gloria Berlier in Turin University, Italy, Dr. Kirill A. Lomachenko, Dr. Ton VW Janssens, Dr. Kirill A. Lomachenko, a French European synchronous radiation facility, Dr. Kirill A. Lomachenko obtained chemistry and materials in 2023. science. Her main research focuses on using the XAS spectrum to establish a structural relationship of new materials.
Volkswagen It is a senior scientist of Danish UMICORE APS. His main research interest is to clarify catalytic reactions and catalysts. After obtaining a doctorate degree in surface science (1993), he became a doctoral degree in the postdoctoral post-doctoral degree of the University of California and the Fritz-Haber Institute from the University of California. In 1998, he joined Haldortopsøe (Topsoe) of Lyngby, Danish, and worked in hydrogen catalysts, methanol to Dutch sugar, and subsequent cars. Since 2017, he has been a member of the Danish Umiko Automotive Catalyst, focusing on the SCR catalyst.
Kirill a. lomachenko Chemical research plans responsible for the BM23 and ID24 XAS beams in charge of European synchronous radiation facilities (France). He completed his doctorate under the co -supervision of the professor. Carlo Lamberti (Turin University in Italy) and Alexander Soldatov (Federal University in South Russia) concentrated in physics, chemistry and materials science. His main research areas are the application of XAS and XES spectrums and related feature technologies to establish a structural relationship between new materials for catalytic, energy storage and gas adsorption.
