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

In this paper, the NOx conversion reduced enormously after the water vapor and sulfur test. Then, the poisoning mechanism of SO2/H2O on In/H-Beta for CH4-SCR was investigated using various characterization techniques such as TPSR, XRD, XPS, and in-situ DRIFTS to elucidate the CH4-SCR process over In/H-Beta catalyst. The results showed that SO2, NO and CH4 had competitive adsorption on the (InO)+ active sites of the catalyst to form sulfate species. H2O adsorbed on the Si-OH(i) and (InO)+ active sites, reduced the adsorption of NO and CH4 and ultimately blocked the catalyst for the CH4-SCR reaction. This study provided insights into the H2O/SO2 poisoning mechanism of the In/H-Beta catalyst, which guide the design of novel catalysts for CH4-SCR.