Hydrogenation of Ethyl Acetate to Ethanol over Bimetallic Cu-Zn/SiO₂Catalysts Prepared by Means of Coprecipitation

Abstract

A series of bimetallic Cu-Zn/SiO 2 catalysts were prepared via thermal decomposition of the as-synthesized CuZn(OH) 4 (H 2 SiO 3 ) 2 ·nH 2 O hydroxides precursors. This highly dispersed Cu-solid base catalyst is extremely effective for hydrogenation of ethyl acetate to ethanol. The reduction and oxidation features of the precursors prepared by coprecipitation method and catalysts were extensively investigated by TGA, XRD, TPR and N 2 -adsorption techniques. Catalytic activity by ethyl acetate hydrogenation of reaction temperatures between 120 and 300 o C, different catalyst calcination and reduction temperatures, different Cu/Zn loadings have been examined extensively. The relation between the performance for hydrogenation of ethyl acetate and the structure of the Cu-solid base catalysts with Zn loading were discussed. The detected conversion of ethyl acetate reached 81.6% with a 93.8% selectivity of ethanol. This investigation of the Cu-Zn/SiO 2 catalyst provides a recently proposed pathway for ethyl acetate hydrogenation reaction to produce ethanol over Cusolid base catalysts.

An Effective CuZn–SiO2 Bimetallic Catalyst Prepared by Hydrolysis Precipitation Method for the Hydrogenation of Methyl Acetate to Ethanol

“…Recently, Zn-modified Cu/SiO 2 catalysts have been applied in multifarious reaction process including esters hydrogenation, the water–gas shift reaction, methanol steam reforming, methanol synthesis, dimethyl ether synthesis, and so on. − The interaction between copper and zinc species has been studied for several decades in CuZn/Al 2 O 3 catalyst for methanol synthesis. Up to now, two major viewpoints about the ZnO effect are generally accepted: (1) the interface between Cu and ZnO provide the active site, (2) the formation of Cu/Zn alloy creates the active site. , Although both viewpoints have been confirmed by experiment and theoretical calculation in methanol synthesis, the doubt about the role of ZnO in the Cu-based catalyst still exists in the esters hydrogenation system.…”

Efficient Synthesis of Cyclohexanol and Ethanol via the Hydrogenation of Acetic Acid‐Derived Cyclohexyl Acetate with the CuxAl1Mn2−x Catalysts

“…As a result, 76.5 % and 63.2 % yields toward ethanol were achieved, respectively. [18,19] In another case, a Cu/ MgOÀ SiO 2 catalyst was prepared by an ammonia-evaporation method towards the hydrogenation of methyl acetate in a fixed-bed continuous flow reactor, showing 80.3 % methyl acetate conversion and 99.0 % selectivity to ethanol. [20] In our previous work, a Cu 9 À Al 0.5 À Mg 1.5 catalyst prepared via a deposition-precipitation (DP) method was investigated in the hydrogenation of ethyl acetate, furnishing 97.8 % ethyl acetate conversion with 98 % selectivity to ethanol and a good lifetime (> 210 h) under mild conditions in a fixed-bed reactor.…”

“…Firstly, the intrinsic ability of the catalysts needs to be further improved because in some cases the conversion or selectivity was below 90 %. [18][19][20] Secondly, according to the literature, the catalyst life of the Cu-based catalysts for the hydrogenation of acetates in fixed-bed reactors was also very limited. [17,22,23] Most important of all, the hydrogenation of CHA to produce CHOL is a relatively new reaction route and would be very meaningful.…”