Ammonia (NH₃) plays a huge role in the future energy industry due to its high hydrogen capacity (17.65%), high energy density ((4.32 kWh L^–1), and clear emission. Moreover, NH₃is regarded as an important chemical for producing plastics, fertilizers, nitric acid, explosives, and intermediates for pharmaceuticals. Industrially, NH₃ production has been carried out by the Haber-Bosch process (HBP), which consumes a large amount of H₂ and requires about 2% of the global energy supply. Electrochemical nitrate reduction to ammonia has been recognized as a promising and emerging technology. Herein, by rationally choosing copper as an active metal and platinum as a promoting metal, we prepared CuPt nanostructures supported on a highly cross-linked peptide bolaamphiphile hydrogel. The synthesized CuPt nanostructures were characterized by XPS, XRD, Rheology, HR-TEM, FE-SEM, and EDS analyses. The developed CuPt(3:1)@hydrogel showed excellent catalytic activity with a maximum faradaic efficiency of 72.33% at -0.1 V (vs RHE) and a relatively high NH₃ yield of 0.71 mg h^–1 mg_cat^–1at -0.3 V (vs RHE) in the alkaline electrolyte (1 M KOH) containing 0.1 M KNO₃. CuPt(3:1)@hydrogel demonstrated a low solution resistance (R_s = 1.58 Ω), low charge transfer resistance (R_ct= 5.58 Ω), and high electrochemical active surface area (3.01X10^-4 cm²) between the dense nanofibrillar network interface of CuPt(3:1)@hydrogel and the electrolyte during NO₃RR performance. The nanofibrillar network of peptide bolaamphipile provides highly exposed catalytic active sites, whereas the synergistic interaction of bimetallic CuPt composition helps to improve the reactivity of these active sites. Control experiments support that the generated NH₃ originated from the NO₃^- reduction rather than any other impurities. Hence, these findings open new avenues for exploring peptide-based nanomaterials for future electrocatalysts.

Deepak Kumar Krishnan K. K. Kori

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