Wang Peng, Yang Xiaodan, Zhang Ye, Gao Yong, Zhang Jinsong
School of Materials Science and Engineering, Northeastern University Shenyang 110819 Liaoning China.
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences Shenyang 110016 Liaoning China
RSC Adv. 2021 Jun 2;11(32):19819-19826. doi: 10.1039/d1ra02533c. eCollection 2021 May 27.
It is essential to improve the catalytic stability of Au-based catalysts for acetylene hydrochlorination. In this study, a novel hollow SiC foam with porous walls (HSF) is proposed to modify the Au catalyst distribution on the foam-based structured catalyst. The scanning electron microscopy and 3D X-ray tomography results showed that the hollow structure and the porous ceramic wall of HSF were successfully obtained. An Au/AC/HSF structured catalyst was prepared by the slurry-coating and impregnation method. Then the effects of the wall pore structure of HSF on the distribution of Au species and the stability of the catalyst were studied by comparison with a hollow SiC foam with compact walls (HSF). The HSF with 3D interconnected hollow channel structure was demonstrated to have a promotion effect on the reaction stability due to its ability to refine the catalyst particles during the impregnation and drying processes. The result indicates that the time on stream of acetylene conversion above 90% over the Au/AC/HSF structured catalyst reaches about 380 h at an acetylene gaseous hourly space velocity of 130 h, which is much longer than that of the Au/AC/HSF. In addition, a bidirectional diffusion effect that can enhance the catalyst distribution by the porous wall of HSF was proposed in this paper. This may have positive significance in the field of preparation of structured catalysts.
提高用于乙炔氢氯化反应的金基催化剂的催化稳定性至关重要。在本研究中，提出了一种具有多孔壁的新型中空碳化硅泡沫（HSF），以改变泡沫基结构化催化剂上金催化剂的分布。扫描电子显微镜和三维X射线断层扫描结果表明，成功获得了HSF的中空结构和多孔陶瓷壁。通过浆料涂覆和浸渍法制备了Au/AC/HSF结构化催化剂。然后，通过与具有致密壁的中空碳化硅泡沫（HSF）进行比较，研究了HSF的壁孔结构对金物种分布和催化剂稳定性的影响。具有三维互连中空通道结构的HSF由于其在浸渍和干燥过程中细化催化剂颗粒的能力，被证明对反应稳定性有促进作用。结果表明，在乙炔气体时空速为130 h时，Au/AC/HSF结构化催化剂上乙炔转化率高于90%的连续运行时间达到约380 h，这比Au/AC/HSF长得多。此外，本文还提出了一种双向扩散效应，即HSF的多孔壁可增强催化剂分布。这可能在结构化催化剂制备领域具有积极意义。
