Mechanism of the arsenic adsorption over Cu/?-Al2O3 SCR catalyst: An experimental combined theoretical analysis

Cu-based oxides are regarded as the promising selective catalytic reduction (SCR) catalysts to alleviate the NOxemission. However, its application is restricted to the irreversible deactivation by arsenic in the flue gas. Identifying the arsenic adsorption on Cu-based catalysts provides a reference to enhance the arsenic resistance of SCR catalyst. In this work, arsenic adsorption over Cu/y-Al2O3 & nbsp;SCR catalyst was studied. From the results of catalytic activity test, Cu/y-Al2O3 exhibited an excellent NO conversion ability at 523 and 573 K, which indicated that it was a superior SCR catalyst even at a low temperature range. Gas constituents in the flue gas significantly affected the arsenic adsorption on Cu/y-Al2O3 catalyst, that a given concentration of O-2, SO2 and NO was beneficial to arsenic adsorption. Furthermore, Al2O3 adsorption on Cu/y-Al2O3 catalyst was simulated through density functional theory (DFT) method. Results showed that the As2O3 adsorption on Cu/y-Al2O3 surface was stronger than that on CuO surface, which were the primary forms of coated copper in Cu/y-Al2O3 catalyst. Besides, O-O bridge site on Cu/ y-Al2O3 surface was the active site for As2O3 adsorption. It indicated that As2O3 adsorption on Cu/y-Al2O3 surface was the main cause for arsenic deposition over Cu/y-Al2O3 catalyst. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.

Automated summary

Cu-based oxides are a promising SCR catalyst for NOx reduction, but their application is limited by irreversible deactivation caused by arsenic. This study investigates the adsorption of arsenic on Cu/y-Al2O3 SCR catalyst and provides insights for enhancing its arsenic resistance.