A general strategy for design SCR catalysts with enhanced resistance to multiple poisons through constructing highly dispersed paired acid-base sites.

The complex composition of solid waste in co-processing within industrial kilns leads to the coexistence of multiple poisons in flue gas, which accelerates the deactivation of SCR catalysts. In this work, solid superacid modified CeO with highly dispersed acid-base sites was constructed, achieving the capture of acidic/basic poisons. Moreover, the designed catalyst retained active sites for the adsorption and activation of NH after poisoning. The sulfated ZrO/CeO exhibited 2.0, 1.1, 2.3, 1.2, and 2.6-fold increase of NO conversion than commercial VO-WO/TiO when Pb, As, Zn, K, and Cd loading. The highly dispersed monodentate sulfate species on the catalyst surface provided abundant acid sites for the capture of basic poisons (e.g., Cd, Pb, K, Zn) and NH adsorption. The basic CeO doped with Zr captured acidic poisons (e.g., As) and promoted the activation of NH due to the high capacity of Ce and oxygen vacancies. Spectroscopic characterization revealed that the highly dispersed acid-base sites along with more Ce species on the catalyst surface facilitated the adsorption and activation of NH, crucial for the formation of the reaction intermediate NHNO. This work may provide an approach to develop efficient SCR catalysts with superior resistance to poisons and reduce the generation of waste catalysts.