The poisoning mechanism of H2O/SO2 to In/H-Beta for selective catalytic reduction of NOx with methane.

In this paper, the NO x conversion reduced enormously after the water vapor and sulfur test. Then, the poisoning mechanism of SO 2 /H 2 O on In/H-Beta for CH 4 -SCR was investigated using various characterization techniques such as TPSR, XRD, XPS, and in-situ DRIFTS to elucidate the CH 4 -SCR process over In/H-Beta catalyst. The results showed that SO 2 , NO and CH 4 had competitive adsorption on the (InO)+ active sites of the catalyst to form sulfate species. H 2 O adsorbed on the Si-OH (i) and (InO)+ active sites, reduced the adsorption of NO and CH 4 and ultimately blocked the catalyst for the CH 4 -SCR reaction. This study provided insights into the H 2 O/SO 2 poisoning mechanism of the In/H-Beta catalyst, which guide the design of novel catalysts for CH 4 -SCR. [Display omitted] • SO 2 competed with NO for adsorption on the surface by interacting with (InO)+. • H 2 O adsorbed on Si-OH (i) , further affecting NO's adsorption. • H 2 O was preferentially adsorbed on the InO+ active sites compared to SO 2 , CH 4 and NO. • SO 2 and H 2 O appeared to exhibit synergistic toxicity in the poisoning of the catalyst. [ABSTRACT FROM AUTHOR]