Development of Highly Active Metallosilicate Catalysts for Propane Aromatization

研究了C2-C20直链饱和烃在MFI结构的ga和zn硅酸盐上的芳构化反应。随着C数的增加，转化率增加，但芳香选择性降低，直至C5。对于高于C6的烃类，由于直接环化，选择性几乎相同。铂掺入硅酸镓后，在保持脱氢能力的同时，减缓了裂解能力，大大提高了芳香族的选择性。进一步证实了Pt改性提高催化剂寿命的有效性，并发现添加碱性组分可以中和表面酸性位点。详细探讨了焦炭的形成机理、焦炭的性质及回火处理方法。采用全自动流动反应器对丙烷芳构化进行了长期催化试验。另一方面，为了了解微孔材料在微孔中的动态扩散过程以及微孔材料的酸性特性，本文提出了一种新的计算化学评价方法。将其应用于该系统，证明它是理解微观现象的有力方法。

Aromatization of C2-C20 straight-chained saturated hydrocarbons was studied on Ga-and Zn-silicates with MFI structure. The conversions increased but the aromatic selectivities decreased with the increase in C number up to C5. For hydrocarbons higher than C6, the selectivities were almost same due to the direct cyclization. The aromatic selectivities were much improved by using Pt incorporated Ga-silicate, which had moderated cracking ability with maintaining the dehydrogenation ability. Effectiveness of Pt modification to improve the catalyst life was reconfirmed and furthermore addition of basic components, which neutralized the surface acidic sites, was also found to be effective. The mechanism of coke formation, property of the formed coke, and rejuvenating treatment method were examined in detail. The long-term catalytic tests for propane aromatization were conducted using a full-automatic flow reactor. On the other hand, to understand the dynamic diffusion process in micropores and the acidic properties of microporous materials, a new evaluating method by computational chemistry was developed. It was applied for this system and proved to be powerful method to comprehend microscopic phenomena.