On the Sn(II) and Sn(IV) incorporation into the AFI-structured AlPO4-based framework: the first significantly acidic SnAPO-5
On the Sn(II) and Sn(IV) incorporation into the AFI-structured AlPO4-based framework: the first significantly acidic SnAPO-5
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DOI：
10.1039/b905057d
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发表时间：
2009-09
影响因子：
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通讯作者：
M. Sánchez-Sánchez-M.-Sánchez-Sánchez-1398732651;R. Grieken;D. Serrano;J. Melero
中科院分区：
文献类型：
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作者：
M. Sánchez-Sánchez-M.-Sánchez-Sánchez-1398732651;R. Grieken;D. Serrano;J. Melero
测试了锡(II)和锡(IV)氯化物作为锡进入AlPO4-5骨架的来源。N-甲基二环己胺(MCHA)被选为结构导向剂，利用其对AFI结构的AlPO4基材料的高度专一性。在广泛的凝胶成分范围内，成功地制备了纯AFI材料，而不受锡源的影响。虽然不同的表征技术的锡(IV)APO-5材料证明了不利的(或至少是低质量的)掺入锡，从以前的研究预期，毫无疑问，正确的锡(II)纳入AlPO4框架。能够被适当地结合到AlPO4-5结构中的锡(II)的量显著高于文献中关于锡(IV)APO-5材料以及本工作中制备的锡(IV)APO-5材料的描述的量。首次考察了AlPO4基微孔催化剂在苯甲醚的Friedel-Craft酰化反应中的催化性能。结果表明，在这些需要酸中心的反应中，锡(IV)APO-5，尤其是锡(II)APO-5是活性催化剂。由于所有测试的AlPO4基材料(纯AlPO4-5、SAPO-5和SnAPO-5)都具有AFI结构和相似的表面积，因此苯甲醚的酰化程度被用作酸强度的间接证明。与Sn2+APO-5相比，纯AlPO4-5的转化率微乎其微，克服了SAPO-5的活性，甚至克服了标准分子筛H-beta的活性。
Both Sn(II) and Sn(IV) chlorides were tested as sources for tin incorporation into an AlPO4-5 framework. N-Methyldicyclohexylamine (MCHA) was chosen as a structure-directing agent, taking advantage of its reported high specificity towards AFI-structured AlPO4-based materials. Pure AFI materials were successfully produced, irrespective of the Sn source in a wide range of gel compositions. Whereas the different characterization techniques of the Sn(IV)APO-5 materials certify the unfavourable (or at least low-quality) incorporation of Sn, as expected from previous studies, there is no doubt about the right Sn(II) incorporation into the AlPO4 framework. The amount of Sn(II) able to be properly incorporated into the AlPO4-5 structure is significantly higher than that described in the literature for Sn(IV)APO-5 materials as well as for the Sn(IV)APO-5 materials prepared in this work. For the first time, AlPO4-based microporous catalysts were tested in the Friedel–Crafts acylation of anisole. Supporting the characterization results, Sn(IV)APO-5 and especially Sn(II)APO-5 were active catalysts in such reactions which require acid centers to take place. Since all tested AlPO4-based materials (pure AlPO4-5, SAPO-5 and SnAPO-5) possess an AFI structure and similar surfaces areas, the extent of the acylation of anisole was taken as indirect proof of acidic strength. The conversion given by pure AlPO4-5 was negligible in comparison with Sn(II)APO-5, which overcomes the activity of the SAPO-5 and even that of a standard zeolite H-beta.