Significant promoting effect of Ce or La on the hydrothermal stability of Cu-SAPO-34 catalyst for NH3-SCR reaction

By Jie Fan, P. Ning, Yancai Wang, Zhongxian Song, Xin Liu, Huimin Wang, J. Wang, Lanying Wang, Qiulin Zhang. Chemical Engineering Journal, 2019

146 citations recorded by the source corpus.

Abstract The effect of Ce or La on the hydrothermal stability of Cu-SAPO-34 catalyst was evaluated by the selective catalytic reduction of NOx by ammonia (NH3-SCR) reaction after hydrothermal aging at 700 °C in 10 vol% H2O/air for 10 h. The hydrothermal stability of Cu-SAPO-34 was dramatically enhanced by introducing small amount Ce or La into Cu-SAPO-34. More than 93% NOx conversion was maintained over the aged Ce or La modified Cu-SAPO-34 at 175–350 °C, while extremely poor NH3-SCR activity was obtained over the aged Cu-SAPO-34. In situ diffuse reflection infrared Fourier transform spectrum (DRIFTS) results illustrated that the hydrothermal treatment cut off the intrinsic “E-R” reaction route over the Cu-SAPO-34 and opened the new reaction pathway (“L-H” mechanism) over the La modified Cu-SAPO-34 catalyst. Additionally, the introduction of Ce or La effectively mitigated the dealumination progress and restrained the aggregation of copper species over Cu-SAPO-34 during the hydrothermal aging, further maintaining the relatively large specific surface area and uniform pore size distribution. Meanwhile, the incorporation of Ce or La enhanced the redox property and stabilized the surface acid sites of Cu-SAPO-34, further facilitating the adsorption and activation of reactants.

Subfields: Materials Chemistry, Mechanical Engineering, Organic Chemistry

View Paper: https://www.semanticscholar.org/paper/83b2389f715c83a81e026a3bf0bd67ef2992d717