The influence of silicon on the catalytic properties of Cu/SAPO-34 for NOx reduction by ammonia-SCR

By Jun Wang, Tie Yu, Xinquan Wang, Gongshin Qi, J. Xue, Meiqing Shen, Wei Li. 2012

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Abstract The effect of Si content in SAPO-34 on NO selective catalytic reduction over Cu/SAPO-34 catalyst was investigated. Three fresh catalysts with different Si contents, prepared by the same procedure, showed different NO conversions from 120 °C to 600 °C. These catalysts were characterized in detail by various techniques (ICP, XRD, SEM, NMR, NH 3 -TPD, H 2 -TPR and EPR). The NH 3 -TPD results indicate that the number of acid sites in Cu/SAPO-34 catalyst increases with increasing Si contents and the SCR activities of the samples correlate well with the number of acidic sites at low temperatures (200 °C). The EPR and H 2 -TPR results show that both the Si and the Al contents affect the number of isolated Cu 2+ ions in Cu/SAPO-34 catalysts. The catalysts aged at 750 °C for 12 h showed higher SCR activities than those of the untreated samples, consistent with the higher numbers of the isolated Cu 2+ ions.

Subfields: Catalysis, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/299b8f2ca001361b072250348e9662a56d61d6f5