2017/04/17 by Hee‐Joon Chun, V. Apaja, Andre Z. Clayborne +2 · 1 citation
Chemical Engineering · Materials Science · Energy · #Ammonia Synthesis and Nitrogen Reduction #Catalytic Processes in Materials Science #Advanced Photocatalysis Techniques
paper · doi:10.1021/acscatal.7b00547
openalex publication_date 2017/04/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Electrocatalytic denitrification is a promising technology for the removal of NO x species in groundwater. However, a lack of understanding of the molecular pathways that control the overpotential and product distribution have limited the development of practical electrocatalysts, and additional atomic-level insights are needed to advance this field. Adsorbed NO has been identified as a key intermediate in the NO x electroreduction network, and the elementary steps by which it decomposes to NH 4 +, N 2, NH 3 OH +, or N 2 O remain a subject of debate. Herein, we report a combined density functional theory (DFT) and kinetic Monte Carlo (kMC) study of this reaction on Pt(100), a catalytic surface that is known to be suitable for the activation of strong covalent bonds, in acidic electrolytes. This approach describes the effects of coverage-dependent adsorbate–adsorbate interactions, water-mediated protonation kinetics and thermodynamics, and transient potential sweeps, on reaction rates and selectivities. The results predict NO stripping curves in excellent agreement with experiments while, at the same time, providing a mechanistic interpretation of observed current peaks. Furthermore, production of NH 4 + products is traced to the rapid kinetics of N–O bond breaking in reactive intermediates, whereas rapid hydrogenation of surface N* species prevent competing pathways from forming either N 2 or N 2 O. The combined DFT-kMC methodology thus provides a unique tool to describe the mechanism and energetics of platinum-catalyzed electroreduction in the nitrogen cycle, and this approach should also find application to related electrocatalytic processes that are of technological and environmental interest.