摘要
研究了工业合成的β沸石对苯-丙烯烷基化反应的催化性能,考察了不同金属改性后对β沸石表面酸性和催化性能的影响。用催速老化方法考察了改性前后催化剂的反应稳定性,并用TPD和IR表征了β沸石的表面酸性质。实验结果表明,β沸石对苯-丙烯烷基化反应有很高的活性和选择性,催化剂的反应稳定性与B酸,L酸量之比有关,反应活性中心主要是中等强度以上的B酸中心,弱酸中心(主要是L酸)起辅助作用。Ga、In、Zn氧化物改性的Hβ沸石提高了反应的稳定性。金属氧化物改性可改变催化剂表面B酸和L酸的比例。
The surface acidities of pure and modified(wilh ⅢA and ⅡB metals) β zeolite were studied by TPD of NH_3 and IR. The alkylation of benzene with propene (or isopropanol) over the β zeolites was examined in a fixed-bed integral reactor.Hβ zeolite has a high catalytic activity for the alkylation of benzene with propene and a fair selectivity to cumene. There are two peaks on the TPD spectra, corresponding to weak and strong acid centers. Modification of Hβ zeolite by some metals changes the ratio of strong acid centers to weak ones and increases alkylation stability by eliminating some strong acid sites. The activity centers for the alkylation of benzene with propene are mainly the moderate and strong B acid sites. The weak acid sites (L acid) may act as auxiliary centers.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1990年第1期16-23,共8页
Journal of Fuel Chemistry and Technology
