Abstract The reaction of carbon oxides and hydrogen in the presence of the Raney nickel catalyst has been used for water synthesis. A procedure has been developed for the recovery and collection of the synthesized water with minimal losses and without deteriorating the 17 O or 18 O isotope enrichment as compared to the initial CO 2 and CO. The recovery of oxygen with high concentrations of 17 O and 18 O isotopes is based on ...