“…The catalytic upgrading of ethanol into butanol through the Guerbet coupling reaction, a well‐known industrial route for higher alcohol synthesis, have attracted widespread attention recently [10,11] . A commonly proposed mechanism for this process consists of a three‐step sequence of reactions, which involves an initial dehydrogenation step to form acetaldehyde, a subsequent aldol self‐condensation reaction to crotonaldehyde/butanal, and the final hydrogenation of the condensation product to butanol, as shown in Scheme 1 [12–14] . Meanwhile, a variety of byproducts, such as ethene, ether, ethyl acetate, hexanol, etc., might be also produced from the competitive side‐reaction owing to the complicated process [13,14] .…”