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The electrochemical synthesis of α ${\alpha }$ ‐amino acids at room temperature and pressure is a sustainable alternative to conventional methods like microbial fermentation and Strecker synthesis. A custom‐built zero‐gap flow electrolyzer was used to study the electrosynthesis of alanine via the electrocatalytic reductive amination (ERA) of the corresponding biomass‐derivable α ${\alpha }$ ‐keto acid precursor – pyruvic acid (PA), and hydroxylamine (NH2OH) at very low pH. Non‐toxic, abundant, and easy to prepare TiO2/Ti electrocatalysts were utilized as the cathode. Three TiO2/Ti felt electrodes with different oxide thicknesses were prepared and their characterization results were correlated with their respective electrochemical performance in terms of Faradaic efficiency η ${\eta }$ , and partial current density j‾ ${\left|\overline{j}\right|}$. Cyclic voltammetry indicated a different electrocatalytic reduction process on hydrothermally treated electrodes, compared to thermally oxidized ones. Hydrothermally treated electrodes were also found to have the thickest porous anatase layer and achieved 50–75 % alanine conversion efficiencies. Optimization showed that the cell potential, reactant flow rate and the PA: NH2OH ratio were crucial parameters in determining the conversion efficiency. η ${\eta }$ and j‾ ${\left|\overline{j}\right|}$ were found to significantly decrease when an excess of is used and, an optimal alanine η ${\eta }$ of 75 % was achieved at 2.0 V applied cell potential and 10 mL/h reactant flow rate. [ABSTRACT FROM AUTHOR]

The electrochemical synthesis of α ${\alpha }$ -amino acids at room temperature and pressure is a sustainable alternative to conventional methods like microbial fermentation and Strecker synthesis. A custom-built zero-gap flow electrolyzer was used to study the electrosynthesis of alanine via the electrocatalytic reductive amination (ERA) of the corresponding biomass-derivable α ${\alpha }$ -keto acid precursor - pyruvic acid (PA), and hydroxylamine (NH 2 OH) at very low pH. Non-toxic, abundant, and easy to prepare TiO 2 /Ti electrocatalysts were utilized as the cathode. Three TiO 2 /Ti felt electrodes with different oxide thicknesses were prepared and their characterization results were correlated with their respective electrochemical performance in terms of Faradaic efficiency η ${\eta }$ , and partial current density j ‾ ${\left|\overline{j}\right|}$ . Cyclic voltammetry indicated a different electrocatalytic reduction process on hydrothermally treated electrodes, compared to thermally oxidized ones. Hydrothermally treated electrodes were also found to have the thickest porous anatase layer and achieved 50-75 % alanine conversion efficiencies. Optimization showed that the cell potential, reactant flow rate and the PA: NH 2 OH ratio were crucial parameters in determining the conversion efficiency. η ${\eta }$ and j ‾ ${\left|\overline{j}\right|}$ were found to significantly decrease when an excess of is used and, an optimal alanine η ${\eta }$ of 75 % was achieved at 2.0 V applied cell potential and 10 mL/h reactant flow rate., (© 2024 The Authors. ChemPlusChem published by Wiley-VCH GmbH.)