English to French Tech/Engineering Chemistry; Chem Sci/Eng a polymer electrolyte fuel cell

A commercially available NAFION® 111 membrane (manufactured by DuPont Co.) was used to evaluate various properties. NAFION® 111 membrane was immersed in a 5% hydrogen peroxide water at 100°C for 30 minutes, immersed in 5% dilute sulfuric acid at 100°C for 30 minutes and then adequately washed with deionized water at 100°C.

j'ai aussi dans le même paragraphe a 5% dilute sulfuric acid= acide sulfurique dilué à 5%

a 5% hydrogen peroxide water = eau contenant 5% de peroxyde d'hydrogène!