Manganese oxide promoter effects in the copper-catalyzed hydrogenation of ethyl acetate

• Published in: Journal of catalysis Vol. 394; pp. 307 - 315
• Main Authors: Beerthuis, Rolf, Visser, Nienke L., van der Hoeven, Jessi E.S., Ngene, Peter, Deeley, Jon M.S., Sunley, Glenn J., de Jong, Krijn P., de Jongh, Petra E.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-02-2021
• Subjects: Carbon; Copper; Heterogeneous catalysis; Hydrogenation; Manganese; Promoter; Water; Promoter; Water; Heterogeneous catalysis; Copper; Hydrogenation; Carbon; Manganese
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2020.11.003

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•A method was developed to tune the MnOx-Cu particle size on graphitic carbon.•The MnOx-Cu particle size was around 6 nm, using 8 wt% Cu and between 0 and 3.4 wt% Mn.•The hydrogenation activity increased 7-fold when using 11 mol% Mn/(Cu + Mn) versus pure Cu.•Apparent activation energy decreased from ~100 (pure Cu) to 52 kJ mol−1 for 11 mol% Mn/(Cu + Mn).•Increasing the water concentration decreased the catalyst activity, yet less for MnOx-promoted Cu.
Supported metal catalysts are widely used in the chemical industry, commonly with added metal oxide promoters to enhance the catalytic performance. Here, we discuss manganese oxide as an efficient promoter for the Cu-based hydrogenation of ethyl acetate; a model hydrogenation reaction. A series of carbon-supported MnOx-Cu catalysts was prepared with 6 nm MnOx-Cu particles, while varying the Mn loading between 0 and 33 mol% Mn/(Cu + Mn), without changing the Cu loading or support structure. At temperatures of 180–210 °C and 30 bar pressure, the addition of 11 mol% Mn to Cu gave a 7-fold enhancement in activity, and better catalyst stability. Furthermore, the apparent activation energy decreased from ~100 to 50 kJ mol−1. State-of-the-art characterization allowed to establish a correlation between catalyst structure and performance.