研究了CuO与γ-Al2O3和CeO2的相互作用,并由此制备出能有效脱除CO,C3H6和NO的催化剂,考察了不同载体表面CuO簇的分散稳定性和耐老化性能.结果发现,随CuO负载量的增加,CuO簇因与CeO2载体的强相互作用而稳定存在;而在γ-Al2O3表面,CuO簇易聚集成较大的颗粒.另一方面,由于CeO2本身较差的热稳定性,表面分散的CuO在950oC高温处理后烧结.因此,基于γ-Al2O3载体优越的耐老化性能,在γ-Al2O3载体分散CeO2,然后再担载CuO,从而得到了稳定的CuO簇,所得催化剂比CuO/γ-A12O3和CuO/CeO2具有更好的催化性能和抗热老化性能.
A strong interaction between a metal oxide and support has long been indicative of its promotion of catalytic activities. In connection with this, we investigated the interaction of CuO with γ-Al2O3 and CeO2 for producing highly efficient catalysts for CO, C3H6, and NO abatement. In particular, the dispersion and thermal aging resistance of CuO clusters on different supports were studied. CuO clusters can be stabilized by interaction with CeO2, while on γ-Al2O3 they aggregated into larger particles at high CuO loadings. On the other hand, due to the poor thermal stability of CeO2, CuO clusters dispersed on it were sintered during an aging treaWaent at 950 ℃. Accordingly, by pre-dispersing CeO2 on 7-A1203 followed by CuO dispersion, stabilized CuO clusters were obtained that were based on the superior aging resistance of the γ-Al2O3 support. Therefore, better catalytic performance and thermal aging properties were obtained with a CuO/CeO2/ γ-Al2O3 catalyst as compared with CuO/γ-Al2O3 and CuO/CeO2 samples.