The direct transformation of ethanol to ethyl acetate over Cu/SiO 2 catalysts that contain copper phyllosilicate

Abstract

Cu/SiO 2 catalysts that contain copper phyllosilicate, were successfully prepared using the ammonia-evaporation method. The catalysts were characterized via XRD, ICP, BET, FTIR, TPR, XPS, NH 3-TPD and FTIR of Pyridine Adsorption techniques. The results demonstrated that the formation of the copper phyllosilicate species significantly affected the structural properties and caused the CuO nanoparticles to become highly dispersed, and the copper phyllosilicate would provide access to the Lewis acidic Cu + species. It was found that the catalyst with a 23.7 wt% copper loading exhibited the best ethanol conversion and ethyl acetate selectivity. When compared to a catalyst with the same copper loading which was prepared with the impregnation method, the higher activity and selectivity of catalysts might be ascribed to the homogenous distribution of copper nanoparticles, which was the active site for the dehydrogenation, and the amount of Lewis acidic Cu + sites active for esterification. The synergetic effect between the Cu 0 and Lewis acidic sites was the key factor to achieve direct transformation of ethanol to ethyl acetate.

Supported Cu catalysts for the hydrogenation of furfural in aqueous phase: effect of support

“…Specifically, Cu/Al 2 O 3 and Cu/ZnO have a reduction peak at around 535 K, suggesting finely dispersed metal Cu species, which is in accordance with the XRD patterns for these samples, which exhibit weak diffraction peaks attributed to metallic Cu. Cu/SiO 2 and Cu/ZSM‐5 also show a single symmetric reduction peak at 587 and 563 K, respectively, which are higher compared with well‐dispersed Cu/SiO 2 and Cu/ZSM‐5 catalysts that have been reported by Yu et al . and Nanba et al ., indicating a larger Cu particles on the surface of the supports.…”

Effect of Si/Al ratio of high-silica HZSM-5 catalysts on the prins condensation of isobutylene and formaldehyde to isoprene

“…NH 3 -TPD analysis was carried out on a self-developed tool. The measurement mechanism was carried out in accordance with the former literature reports [12]. Pyridine adsorption fourier transform infrared (FTIR) spectrum was attained in accordance with the literature as well [13].…”

Mechanism of Forming Nanodisperse Copper Silicate Powder During Anodic Polzrization of Copper Electrode in Potassium Silicate Solution

“…-on the anode there is observed copper electrode dissolution according reactions (2,3). Copper hydroxide formed by reaction (3) reacts with the potassium silicate present in the solution and forms by reaction (4) copper silicate of bright blue color.…”

“…Similarly to [2], the authors of [3] describe the good catalytic activity of the Cu/SiO 2 -catalyst due to the presence of finely dispersed copper slaty silicate. The difference between the works [2] and [3] is that the Cu/SiO 2 -catalyst was obtained by the sol-gel method. However, in [4], although the Cu/SiO 2 -catalyst is also obtained and its structural properties are studied, good catalytic properties are attributed to the presence of copper nanoparticles in the silica gel.…”

“…[2] describe the Cu/SiO 2 -catalysts that contain slaty copper silicate, it has been shown that owing to forming highly disperse copper phyllosilicates, these compounds are effective catalysts for converting ethanol to ethyl acetate. Similarly to [2], the authors of [3] describe the good catalytic activity of the Cu/SiO 2 -catalyst due to the presence of finely dispersed copper slaty silicate. The difference between the works [2] and [3] is that the Cu/SiO 2 -catalyst was obtained by the sol-gel method.…”