Incorporation of cationic indium species into zeolite beta by template-induced reductive solid-state ion exchange
Incorporation of cationic indium species into zeolite beta by template-induced reductive solid-state ion exchange
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通过模板诱导还原固态离子交换将阳离子铟物种掺入沸石β
DOI：
10.1039/a907806a
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发表时间：
1999
影响因子：
3.3
通讯作者：
H. Beyer
中科院分区：
文献类型：
--
作者：
Y. Neinska;R. M. Mihályi;V. Mavrodinova;C. Minchev;H. Beyer
研究发现，在惰性气体气氛或高真空中模板 (TEA) 热分解过程中，结晶 In2O3 和合成的沸石 β (TEA-β) 前体的机械混合物中会发生还原固态离子交换 (RSSIE)。事实证明，模板的气态分解产物作为还原剂在该过程中起决定性作用，导致单价铟阳离子并入沸石结构中。因此，在氧化气氛中模板分解期间没有观察到In 2 O 3 和沸石组分之间的反应。在与热模板分解相关的 RSSIE 后，In+ 和 InO+ 晶格阳离子都可以通过典型的红外光谱带检测到，归因于这些离子与吸附的吡啶的相互作用。三价铟物质可能是通过氧化还原过程形成的，该过程涉及质子（内部硅烷醇基团）还原为 H2 以及 In+ 氧化为 InO+。与此结论一致的是，部分 In+ 阳离子在与水接触时转化为 InO+。
Reductive solid-state ion exchange (RSSIE) was found to proceed in mechanical mixtures of crystalline In2O3 and as-synthesized precursors of zeolite beta (TEA-beta) during thermal decomposition of the template (TEA) in an inert gas atmosphere or high vacuum. It was evidenced that gaseous decomposition products of the template play the decisive role as reductants in this process, which results in the incorporation of univalent indium cations into the zeolite structure. Accordingly, no reaction between In2O3 and the zeolitic component was observed during template decomposition in an oxidizing atmosphere. After RSSIE associated with thermal template decomposition both In+ and InO+ lattice cations could be detected by typical IR spectroscopic bands attributed to interactions of these ions with adsorbed pyridine. The trivalent indium species are probably formed by a redox process involving the reduction of protons (internal silanol groups) to H2 and oxidation of In+ into InO+. In line with this conclusion is the finding that part of the In+ cations are converted into InO+ upon contact with water.