Electrochemical　hydrogenation　of　unsaturated　organic　compounds　is　emerging　as　a　very　promising　alternative　to　the　conventional　transition-metal-catalyzed　transformation　as　it　avoids　the　preparation,　transportation,　and　storage　of　pressured　molecule　hydrogen　(H2).　Besides　the　direct　usage　of　the　on-site-generated　H2　on　the　cathode　surface,　the　electrochemical　means　also　provide　opportunities　for　novel　hydrogenation　reactions　of　unsaturated　hydrocarbons,　especially　electrochemical　Birch　reduction.　Another　attractive　aspect　of　such　an　approach　is　the　possibility　of　highly　selective　deuteration　of　unsaturated　hydrocarbons　with　the　readily　available,　cost-effective　deuterium　source,　D2O.　©　2021　Elsevier　B.V.