Mesoporous Silica-Encapsulated Cu Nanoparticles with Enhanced Performance for Ethanol Dehydrogenation to Acetaldehyde
Chao Tian, Yinghong Yue, Changxi Miao, Weiming Hua, Zi Gao
Abstract
The selective dehydrogenation of ethanol to acetaldehyde over copper-based catalysts is a highly desirable solution for biomass valorization but with a significant challenge of severe deactivation caused by Cu sintering. Herein, a series of mesoporous silica-encapsulated nano-Cu catalysts (Cu@mSiO 2 ) with different Cu loadings of 1–7 wt % were prepared via a modified Stöber method for ethanol dehydrogenation to acetaldehyde. The as-synthesized Cu@mSiO 2 catalysts were characterized by XRD, N 2 adsorption, SEM, TEM, XPS, and TPR. The 7Cu@mSiO 2 catalyst exhibits a stable acetaldehyde yield of around 84% over 100 h on stream at 260 °C and a WHSV of 1.5 h –1, stemming from the spatial confinement effect of the mesoporous silica shell on the Cu nanoparticles. Cu + and Cu 0 species coexisting on the catalyst conduct as synergistic dual active sites for the titled reaction. The acetaldehyde productivity can be controlled by adjusting the Cu + /(Cu 0 + Cu + ) ratio on catalysts.