Abstract:

A direct sediment reactor was coupled with a ceramic membrane for the preparation of high-activity CuCl particles with spherical structure. The effects of the membrane pore size, types of stabilizer, concentration of Cu²⁺ as well as the dispersed phase flow rate on the size and uniformity of the particles were investigated. The catalytic properties of these CuCl particles were explored via Rochow reaction. The results showed that the average particle size of CuCl decreased with the decrease of membrane pore size. The morphology of the particles changed from triangular structure to spherical when adding polyvinylpyrrolidine(PVP) to the continuous and dispersion phase. The uniform spherical CuCl particles, with the average size of 5.1 mm, were obtained under the conditions that the dispersed phase flow rate of Na₂SO₃ with a ceramic membrane of 0.05 mm pore size was 40 ml·min^-1, the concentration of Cu²⁺ was 0.1 mol·L^-1 and the concentration of PVP was 1 mg·ml^-1. The catalytic performance of the uniform spherical CuCl particles, with the dimethyldichlorosilane selectivity of 94% and the Si conversion of 38%, is much better than those of the commercial CuCl particles. Regular spherical particles have a higher selectivity of M2 compared to the triangular particles.

Key words: cuprous chloride, membranes, dimethyldichlorosilane, catalyst, fixed-bed

摘要：

将沉淀反应器与陶瓷膜耦合构成一体式膜反应器,用于制备单分散高活性球形CuCl颗粒。考察陶瓷膜孔径、操作条件和沉淀反应条件对CuCl颗粒形貌和粒径分布的影响,评价氯化亚铜的催化性能。结果表明,陶瓷膜的孔径对CuCl平均粒径影响显著,但对颗粒形貌影响不大;稳定剂对催化剂形貌影响显著,聚乙烯吡咯烷酮K-30 (PVP)的加入使CuCl颗粒由三角形变为球形,使得颗粒粒径更加均一。在铜离子浓度为0.1 mol·L^-1,PVP浓度为1 mg·ml^-1和进料速率为40 ml·min^-1的条件下,采用平均孔径为0.05 mm的陶瓷膜分散Na₂SO₃溶液,可以制备出平均粒径为5.1 mm的单分散球形CuCl颗粒;该颗粒用于直接法制备有机硅单体的反应中,二甲基二氯硅烷的选择性和硅粉的转化率分别为94%和38%,优于商业化氯化亚铜的催化性能。通过比较不同制备条件下氯化亚铜颗粒的催化性能,发现相比于三角形颗粒,形貌规整的球形氯化亚铜对M2的选择性更高。

关键词: 氯化亚铜, 膜, 二甲基二氯硅烷, 催化剂, 固定床