Promotion effect of Bi species in Cu/Bi/MCM-41 catalysts for 1,4-butynediol synthesis by ethynylation of formaldehyde

摘要

A Cu/Bi-based catalyst was used in the ethynylation of formaldehyde for 1,4-butynediol synthesis. Although the Cu/Bi-based catalyst and the correlation between structures and performance have been extensively studied, the influence of Bi species on catalyst activity is unclear. Here, a series of Cu/Bi/MCM-41 catalysts prepared by a facile impregnation method was characterized through X-ray diffraction, H-2 temperature-programmed reduction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and nitrogen physisorption. 25Cu/8Bi/MCM-41 and 25Cu6Bi/MCM-41 exhibited higher activity and excellent selectivity compared with commercial catalysts and other Cu/Bi/MCM-41 catalysts. These improvements were attributed to the synergetic and electron transfer effects between Cu and Bi species. The appropriate amount of Bi species was also advantageous over CuO particles given its small size and good dispersal on MCM-41. Furthermore, Bi species could weaken the interaction between CuO and MCM-41, contributing to reduction of CuO to Cu2C2.