正庚烷在Ni-Sn/SAPO-11催化剂上的临氢异构化反应

分别以浸渍法和分步浸渍法制备了Ni/SAPO-11催化剂和Ni-Sn/SAPO-11双金属催化剂,利用XRD、F T-IR、NH_3-TPD、Py-IR、SEM等手段对其进行了表征,考察了Sn含量对分子筛结构和酸性的影响,并以正庚烷临氢异构化为探针反应,考察了Sn含量及反应条件对催化剂临氢异构化性能的影响.结果表明,在我们所考察的Sn含量范围(加入锡含量)内,所制备的催化剂均能保持SAPO-11分子筛晶相,金属Sn均可调节催化剂酸性.加入Sn可以明显提高正庚烷的转化率和异庚烷的选择性,其中,在氢烃比n(H_2)/n(n-C_7H_(16))为14、H_2流速为30m L/min、还原温度为430℃、还原时间为5 h、反应温度为300℃、反应时间为5 h、重时空速(WHSV)为6.8 h-1、反应压力为常压条件下,5%Ni-4%Sn/SAPO-11催化剂的催化性能较佳,其正庚烷转化率可达43%,异庚烷的选择性可达71%.

The Hydroisomerization of n-Heptane on Ni-Sn/SAPO-11 Catalyst

Ni/SAPO-11 catalyst and Ni-Sn/SAPO-11 bimetallic catalyst were prepared by impregnation and step by step impregnation method,respectively.The influences of Sn content on the structure and acidity of the molecular sieve were investigated by XRD,FT-IR,NH3-TPD,Py-IR and SEM characterizations.Besides,the effect of Sn content and reaction conditions on the isomerization performance of the catalyts was examined by n-heptane hydroisomerization reaction.The results showed that the catalysts with different Sn content were able to maintain the crys talline phase of SAPO-11 molecular sieve and adjust the acidity of catalyst in the investigated content.The addition of Sn can significantly improve both the conversion of n-heptane and the selectivity of isoheptane.The conversion and isomerization selectivity of 5％/Ni-4％ Sn/SAPO-11 catalyst can reach 43％ and 71％,respectively,when n(H2)/n(n-C7 H16) was 14,H2 flow was 30 mL/min,reduction temperature was 430 ℃,reduction time was 5 h,reaction temperature was 300 ℃,reaction time was 5 h,WHSV was 6.8 h-1 and reaction pressure was atmospheric pressure.