One-step synthesis of Cu-Co alloy/Mn2O3-Al2O3 composites and their application in higher alcohol synthesis from syngas

Cu-Co alloy/Mn2O3-Al2O3 composites were synthesized by a facile one-step sol gel method using citric acid as a chelating agent. The catalytic performance of the as-prepared catalysts was investigated in reaction of CO hydrogenation to higher alcohols. According to the characterization data obtained by TG-DSC, XRD, TPR, BET, ICP, SEM, TEM and XPS, a stronger interaction between the Cu and Co ions in the CuCo2O4 particles led to the formation of Cu-Co alloy in the reduced catalysts, and the Mn/Al molar ratio significantly influenced the performance of the catalysts. Mn2O3-Al2O3 composites reduce the unwanted CoAl2O4 spinel phase, offer tunable pore sizes and surface areas, and also appear to act as barriers to hinder the Cu-Co alloy particles sintering. The results suggest that the metal nanoparticles of Cu-Co alloy together with Mn2O3-Al2O3 contributed to the high selectivity of higher alcohols as well as the good stability. A Mn/Al molar ratio of 5/3 was found to be most suitable for the catalyst properties in terms of activity and product distribution. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.