The role of metal sites during the coupled hydrogenation and ring opening of tetralin on bifunctional Pt(Ir)/USY catalysts
The role of metal sites during the coupled hydrogenation and ring opening of tetralin on bifunctional Pt(Ir)/USY catalysts
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DOI：
10.1016/j.apcata.2004.02.037
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发表时间：
2004-07
影响因子：
5.5
通讯作者：
M. Arribas;P. Concepción;Agustín Martínez
中科院分区：
文献类型：
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作者：
M. Arribas;P. Concepción;Agustín Martínez
考察了双功能Pt/USY催化剂中金属功能对四氢萘加氢开环反应的影响。开环反应的关键步骤是萘烷C6环的异构化（缩环）。与单官能USY样品相比，双官能Pt/USY催化剂中Pt的存在显著增加了异构化速率并因此增加了ROP的形成。高十六烷ROP的形成随着Pt和酸位点之间的接近度的增加以及随着在0.25- 4 wt.%范围内的Pt负载（即金属/酸比）的增加而增加。环烷烃的开环被认为只发生在沸石的布朗斯特酸位点上。将氢解金属（Ir）掺入双功能Pt/USY催化剂中不会导致ROP形成的进一步增加，并且显著降低了Pt的耐硫性。这是由于在Pt位上的高电子密度诱导的Ir在Pt-Ir粒子，如XPS所证明的。
The influence of the metal function in bifunctional Pt/USY catalysts in the combined hydrogenation and ring opening of tetralin has been investigated. The key step in the reaction pathway leading to the formation of the desired ring opening products (ROPs) was the isomerization (ring contraction) of the C6naphthenic rings of decalins. The presence of Pt in the bifunctional Pt/USY catalyst significantly increased the rate of isomerization and hence the formation of ROP as compared to the monofunctional USY sample. The formation of the high cetane ROP increased with increasing the proximity between the Pt and acid sites and with increasing the Pt loading (i.e. the metal/acid ratio) in the range of 0.25–4wt.%. Ring opening of naphthenes was seen to occur exclusively on the Brönsted acid sites of the zeolite. Incorporation of a hydrogenolysis metal (Ir) to the bifunctional Pt/USY catalyst did not lead to a further increase in the formation of ROP and significantly reduced the sulfur tolerance of Pt. This was ascribed to a higher electron density on the Pt sites induced by Ir in bimetallic Pt–Ir particles, as evidenced by XPS.