The acidity and pore structure of zeolite catalysts play a crucial role in the selectivity and stability of C4 alkylation due to the synergistic effect of reaction activity and diffusion. Herein, the effect of three acidic beta zeolites with different Si/Al ratios on adsorption, diffusion, and catalytic performance was studied using experiments and molecular simulations. The beta zeolite with the lower Si/Al ratio leads to the faster relative diffusion of isobutane to 1-butene and the smaller adsorption amount of alkylate products. Furthermore, the diffusion of molecules in the zigzag channel along the direction of beta zeolites is much slower than other two directions. The experimental results indicate that lower Si/Al ratio cause the higher content of strong BAS in the zeolite, resulting in the higher hydride activity and the longer catalytic lifetime. This work provides a theoretical basis for the development of high catalytic activity zeolite catalysts.

中文翻译：

---

结合实验和分子模拟揭示低硅铝比β沸石对C4烷基化的增强催化性能


由于反应活性和扩散的协同作用，沸石催化剂的酸性和孔结构对C4烷基化的选择性和稳定性起着至关重要的作用。在此，通过实验和分子模拟研究了三种不同Si/Al比的酸性β沸石对吸附、扩散和催化性能的影响。 Si/Al比越低的β沸石，异丁烷向1-丁烯的相对扩散速度越快，烷基化物产物的吸附量越小。此外，Z字形通道中分子沿β沸石方向的扩散比其他两个方向慢得多。实验结果表明，较低的Si/Al比导致沸石中强BAS含量较高，从而导致较高的氢化物活性和较长的催化寿命。该工作为高催化活性沸石催化剂的开发提供了理论基础。