Primitive Basic Amino Acids Promote Mineral-Catalyzed Electrochemical Reduction of H⁺ and CO₂

Early in the history of life, mineral surfaces, such as the NiFeS mineral violarite (FeNi₂S₄), may have been the primary catalysts. How these primitive chemical systems could have undergone robust chemical evolution remains unknown. Here, we show that simple amino acids, such as diaminobutyric acid (DAB), can accelerate H⁺ and/or CO₂ electrochemical reduction on violarite. Reactions performed with structurally similar compounds demonstrate that both amino groups of DAB participate in HER catalytic enhancement. Spectroscopic analyses suggest that the role of DAB is to deliver protons to the mineral surface. The observation that simple basic amino acids can enhance surface-supported electrochemistry reveals that amino acids could have produced a positive feedback that promoted metabolic complexification even before their eventual incorporation into complex peptide or protein catalysts.