Due to lower bond dissociation energy of H—O— H bonds in water than D—O—D bonds in ${{D}{2}}$O, electrolysis of H20 is much faster that of ${{D}{2}}$O.
Due to lower bond dissociation energy of H—O— H bonds in water than D—O—D bonds in ${{D}{2}}$O, electrolysis of H20 is much faster that of ${{D}{2}}$O.