In this study, we have synthesized four MFI-type borosilicate zeolites with different B/Si ratios using tetrapropylammonium (TPA⁺). The preferred location of boron atoms and structural roles of TPA⁺ were investigated by Rietveld refinement. It revealed that boron-rich position T9 locates in the four-ring of mel composition building unit (CBU) and T5 locates in the five-rings of mfi CBU. Inspired by the structural roles of TPA⁺ in this series of BMFI-TPA samples, we successfully replaced TPA⁺ by Na⁺ and commercialized linear organic molecules for synthesizing MFI-type borosilicates. Using this strategy, another five BMFI samples were obtained. Two of them are well-crystallized without any impurity, which enables us to further investigate the structural information. The results show that boron-rich positions were also in the four- and five-rings. Moreover, the locations of structural-directing agents were consistent with what we expected. The preferred locations of boron atoms unravelled here may provide a new way of tailoring locations of Brønsted acids.

在这项研究中，我们使用四丙基铵（TPA ⁺）合成了四种具有不同B / Si比的MFI型硼硅酸盐沸石。通过Rietveld精炼研究了硼原子的优选位置和TPA ^+的结构作用。结果表明，富硼位置T9位于mel组成单元（CBU）的四环中，T5位于mfi CBU的五环中。由TPA的结构作用的启发⁺在这一系列BMFI-TPA的样品，我们成功地替代TPA ⁺被Na ⁺和商业化的线性有机分子合成MFI型硼硅酸盐。使用该策略，又获得了五个BMFI样本。它们中的两个结晶良好，没有任何杂质，这使我们能够进一步研究结构信息。结果表明，富硼位置也在四环和五环中。此外，结构导向剂的位置与我们预期的一致。此处解开的硼原子的优选位置可能提供一种调整布朗斯台德酸位置的新方法。