Efficient Synthesis of Amino Acids via Electrochemical Hydrogenation

Abstract

Electrochemical hydrogenation of non-fossil resources to produce value added chemicals has great potential to contribute to realization of sustainable material supply. In this article, we introduce electrochemical synthesis of nine amino acids from biomass-derivable α-keto acids and NH₂OH with high Faradaic efficiencies (FEs) of 60 – 99% using earth-abundant TiO₂ catalyst. We also introduce continuous electrosynthesis of alanine using newly designed flow-type electrochemical reactor equipped with TiO₂ cathode catalyst. Furthermore, we present our recent efforts on developing electrocatalytic system for utilizing oxalic acid, which can be easily produced from agro-waste, as a starting material of amino acid synthesis. Glycine and its intermediate, glyoxylic acid oxime, were electrochemically synthesized from oxalic acid and NH₂OH in one-step with FE of 28 and 28%, respectively.