“…Ethanol is a promising renewable raw material 1–3 for the production of value‐added chemicals, e.g., acetaldehyde 4–6, acetic acid 7, ethyl acetate 8, butadiene 9, diethoxyethane 10, hydrogen 11, butanol 12–14, and ethylene 15. Among these products, acetaldehyde is an important raw material for the production of acetic acid, acetic anhydride, cyanohydrin, acrylonitrile, acrylic acid esters, lactic acid, etc.…”