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 degrees 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 similar to 100 to 50 kJ mol(-1). State-of-the-art characterization allowed to establish a correlation between catalyst structure and performance. (c) 2020 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).