Wickert, LeonLeonWickertPellumbi, KevinjeorjiosKevinjeorjiosPellumbiKleinhaus, Julian T.Julian T.KleinhausWolf, JonasJonasWolfjunge Puring, KaiKaijunge PuringSiegmund, DanielDanielSiegmundApfel, Ulf-PeterUlf-PeterApfel2024-04-222024-04-222024https://publica.fraunhofer.de/handle/publica/46623210.1002/cite.202300155Electrochemical hydrogenations (EChH) constitute a sustainable alternative to conventional thermocatalytic hydrogenation. Here, we explored the EChH of the vitamin E and A synthon 2-methyl-3-butyn-2-ol in a scalable zero-gap electrolyzer and revealed crucial effects of electrolyte composition and convection parameters to consider for optimization. We show that high Faraday efficiencies can be achieved with low to moderate concentrations of neutral or alkaline electrolytes. While the flow rate has a strong impact on performance, electrode compression and cell orientation can be used for fine tuning. We achieved a Faraday efficiency of up to 69 % for the targeted semi-hydrogenated product at current densities of 80 mA cm-2 at 2.2 V cell voltage and a concentration of 1 M 2-methyl-3-butyn-2-ol.enAlkynolsElectrocatalytichydrogenationelectrolyte solutionelectrosynthesischemistry, sustainablejournal article