Until now, selective catalytic reduction by ammonia (NH3-SCR) is considered as an effective technique to eliminate the NOxin the lean-burn condition. In the practical applications, the NH3-SCR catalyst needs to havebothexcellent high-temperature (HT) and low-temperature (LT) hydrothermal stabilities and catalytic performance.Among the catalysts, Cu-exchanged silicoaluminophosphates (SAPOs)-based ones are attractingincreasingattentiondue to their excellent HT hydrothermal stabilities. However, SAPOs are subject to the notorious LThydrothermal stability.
In this article, they report a catalyst,Cu2+loading SAPO-17, synthesized bytheinexpensive commercialized cyclohexylamine (CHA), which shows promising catalytic performance and HT and LT hydrothermal stabilities.
This work was published in Chinese Journal of Catalysis on November 5.
Left:The locations of CHAs and hydroxide groups ineriandcancages, respectively. Right:Fresh, 973 K aged and 353 K aged NH3-SCR performance of Cu-SAPO-17-8.0%-0.22.
Aftersystematic investigations regarding the optimization of Si and Cu2+contents, it turns out that Cu-SAPO-17-8.0%-0.22 can maintain over 90% fresh activity after aged at 353 K for 24 h and shows >50% NO conversion at 473 K after aged at 973 K for 16 h.
Moreover, the locations of CHAs, host-guest interaction, andtheBr➢nsted acidic siteswere investigated byRietveld refinement against powder X-ray diffraction data of as-made SAPO-17-8.0%. The refinement results show that 1) there are two CHAs within oneericage and 2) the protonated CHA forms the hydrogen bond with framework O4, which indicates the proton bonded with O4 will be theBr➢nsted acidic site after the calcination.
This work was supported byNatural Science Foundation of China and the Key Research Program of Frontier Sciences, CAS.
Cu-SAPO-17: A novel catalyst for selective catalytic reduction of Nox.Xiaona Liu, Yi Cao, Nana Yan, Chao Ma, Lei Cao, Peng Guo*, Peng Tian*, Zhongmin Liu*, Chinese Journal of Catalysis, 41(11):1715-1722, 2020.
