Development of Highly Active Metallosilicate Catalysts for Propane Aromatization

研究了C2-C20直链饱和烃在具有MFI结构的硅酸盐上的芳构化反应。当C数达到C5时，随着C数的增加，转化率增加，芳烃选择性降低。对于C6以上的碳氢化合物，由于直接环化反应，选择性几乎相同。掺铂镓硅酸盐催化剂的芳烃选择性有较大提高，在保持脱氢能力的同时，具有缓和裂化能力的作用。再次证实了铂的改性对提高催化剂寿命的有效性，此外，添加碱性组分中和了表面酸性中心也是有效的。对结焦机理、结焦特性及返老性处理方法进行了详细的研究。在全自动流动反应器上进行了丙烷芳构化的长期催化试验。另一方面，为了了解微孔内的动态扩散过程和微孔材料的酸性，提出了一种新的计算化学评价方法。将其应用于该系统，证明是理解微观现象的有力手段。

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.