Oxidative esterification of aliphatic aldehydes and alcohols with ethanol over gold nanoparticle catalysts in batch and continuous flow reactors

•Au/ZnO showed the highest catalytic activity and selectivity for base-free selective esterification of octanal and 1-octanol with ethanol.•Ethyl octanoate was continuously obtained using Au/ZnO by a flow system, and its catalytic activity was maintained for 20 h.•This catalytic system can be used in new green processes for producing high-value aliphatic ethyl esters.