Active and stable Cu doped NiMgAlO catalysts for upgrading ethanol to n-butanol

Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimized 2%Cu-NiMgAlO catalyst, ethanol conversion and n-butanol selectivity were enhanced to 30.0% and 64.2%, respectively, in 200 h time on stream at 523 K. According to physicochemical characterizations and theoretical calculations, the key role of multiple active sites in this reaction was extensively investigated. The plate-like structure of hydrotalcite was maintained over 2%Cu-NiMgAlO catalysts, with an average Ni particle size of ca. 5.4 nm. The presence of Cu species created CuNi alloy sites and Lewis acid-base pairs, and increased hydrogen transfer and condensation reactions, resulting in elevated ethanol conversion and n-butanol selectivity. Additionally, CuNi alloy had a strong interaction with CuNiMgAl oxides, forming homogeneous boundary due to their close ionic radius and lattice matching, and afforded the long time stability in the ethanol to n-butanol reaction. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

In this study, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. The optimized 2%Cu-NiMgAlO catalyst showed enhanced ethanol conversion and n-butanol selectivity in a 200-hour reaction time. The key role of multiple active sites in this reaction was extensively investigated.