 World War I urged most chemists to work on urgent technological problems, and Matignon had studied the water-sodium sulfate-ammonium system aiming for the production of sulfuric acid.He also worked on the stability of the ammonium carbonate-urea system, which was important for fertilizers, and discovered an iron-alumina catalyst for the synthesis of ammonia.By applying an oxidation reaction to a cargo of sugar spoiled by seawater he managed to convert it into oxalic acid.