关键词: 棕榈酸甲酯, 加氢, 铜基催化剂, Cu-ZrO₂, 脂肪醇

Abstract:

High-carbon alcohols are important chemical raw materials and have extensive applications in the fields of chemistry, chemical engineering, and pharmaceuticals. Converting fatty acids or fatty acid methyl esters from waste oil into high-carbon alcohols through hydrogenation has attracted increasing attention. In this study, a series of Cu-ZrO₂ catalysts were prepared by a citric acid-assisted sol-gel method. Results reveal that Cu-ZrO₂ catalysts prepared by the sol-gel method mainly exist in the form of tetragonal ZrO₂with loaded copper species. There is a certain metal-support interaction between metallic Cu and the ZrO₂ support, and ZrO₂ crystal phase can be retained during the harsh catalytic reaction conditions. X-ray photoelectron spectroscopy results show that Cu⁰ species are the key active centers. When the Cu⁰ content is insufficient, the conversion rate of methyl palmitate increases with the increase of Cu⁰ content. When the Cu⁰ content is sufficient, Cu⁺ and Cu⁰ have a synergistic effect on the hydrogenation reaction. Catalyst dosage, reaction time, reaction temperature and hydrogen pressure were found to have significant effects on the catalytic transformation of methyl palmitate. Increase of reaction temperature can significantly improve the conversion of methyl palmitate. However, excessive temperature can easily induce the dehydration of the generated hexadecanol into by-products such as hexadecane. The conversion of methyl palmitate can be up to 95.1%, and the yield of hexadecanol can reach 91.1% under the conditions of 10% copper loading, 300℃, 6MPa H₂ pressure and 2h reaction.

Key words: methyl palmitate, hydrogenation, copper-based catalysts, Cu-ZrO₂, fatty alcohols