微反应器中超声对Cu-ZnO催化剂制备过程的影响

Effects of ultrasound on the preparation of Cu-ZnO catalysts in a microreactor

利用超声改变微反应器中的流动混合情况,研究其对Cu-ZnO催化剂制备过程的影响。采用X射线衍射(XRD)、X射线光电子能谱(XPS)和氢气程序升温还原(H2-TPR)研究沉淀物到催化剂的演变过程中不同超声强度对其影响。结果表明,超声强度增加,初始沉淀物中Cu-Zn分布更均匀,锌孔雀石前驱体中Zn含量增加。焙烧得到的氧化物中铜锌组分分散性更好、相互作用力更强,最终使催化活性升高。研究表明,在微反应器共沉淀过程中的条件变化导致沉淀物的结构差异,在后续结构演变过程中得以保持,并影响催化剂的结构和性能。

Effects of flow mixing on the preparation of Cu-ZnO catalysts were studied using ultrasound to change the flow status in a microreactor. X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and hydrogen temperature programmed reduction(H2-TPR) were used to study the effects of ultrasonic intensities on the evolution of precipitates to catalysts. The results show that Cu-Zn distribution in the initial precipitate becomes more uniform as ultrasonic intensity increases and more zinc is incorporated into the precursor, which leads to better dispersibility and stronger interaction between copper and zinc in the calcined oxide, and enhances catalytic activity. This study reveals that different conditions of co-precipitation in microreactors lead to structural differences of precipitates, which maintains during subsequent structural evolution and further affects catalyst structure and performance.