Low–temperature exchange of hydrogen and deuterium between molecular ethanol and water on Au(111)

•Temperature programmed desorption shows that the exchange of hydrogen and deuterium occurs below 200 K on Au(111).•The exchange of hydrogen and deuterium between ethanol and water molecules occurs without the presence of a reactive surface species or reactive substrate.•Isotopic studies show that the exchange occurs between both ethanol/deuterated water and ethanol–OD/water adsorbates on Au(111).•The formation of ethanol/water hydrogen–bonded networks on Au(111) is expected to facilitate the concerted motion of hydrogen/deuterium atoms at low temperatures.