Dehydroisomerization of butane into isobutene on Pt-Sn intermetallic compounds supported on H-SAPO-11
Dehydroisomerization of butane into isobutene on Pt-Sn intermetallic compounds supported on H-SAPO-11
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DOI：
10.1016/j.jcat.2006.05.018
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发表时间：
2006-07
影响因子：
7.3
通讯作者：
T. Komatsu;H. Ikenaga
中科院分区：
文献类型：
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作者：
T. Komatsu;H. Ikenaga
以分子筛为载体的铂基催化剂用于丁烷脱氢异构化制异丁烯反应。在各种沸石中，富硅H-SAPO-11是最适合于在较高丁烷转化率下获得高异丁烯选择性的沸石。采用氨吸附、29 Si MAS NMR和异丙苯裂解等方法对富硅H-SAPO-11的酸中心进行了表征。在Pt/H-SAPO-11上添加Sn、Pb、Zn和In等第二元素，抑制了Pt的氢解活性，降低了甲烷选择性。在第二种元素中，锡是获得更高异丁烯选择性的最有效的添加剂。XRD分析表明，Pt-Sn金属间化合物Pt 3Sn、PtSn和PtSn 2的形成。通过Pt的分散度和CO吸附的红外光谱表征了Pt-Sn催化剂颗粒的表面，提出了表面金属间化合物的形成是通过系综效应阻碍氢解的机理。
The dehydroisomerization of butane to form isobutene was carried out on Pt-based bimetallic catalysts supported on zeolite. Among various zeolites, Si-rich H-SAPO-11 was most appropriate for obtaining high selectivity to isobutene at higher butane conversions. The acid sites of Si-rich H-SAPO-11 were characterized by ammonia adsorption,29Si MAS NMR, and the cracking of cumene. The addition of second elements, such as Sn, Pb, Zn and In, onto Pt/H-SAPO-11 retarded the hydrogenolysis activity of Pt, resulting in decreased methane selectivity. Among the second elements, tin was the most effective additive for obtaining higher isobutene selectivity. The formation of Pt–Sn intermetallic compounds, Pt3Sn, PtSn, and PtSn2, was revealed by XRD. The surface of Pt–Sn bimetallic particles was characterized through the dispersion of Pt and IR spectra of adsorbed CO. The formation of surface intermetallic compounds is proposed to retard hydrogenolysis by the ensemble effect.