Tuning Nitrate Electroreduction on Pt Single Crystals via Bulk Pd Alloying: A Combined Kinetic and DFT Approach

[EN] The electrochemical nitrate reduction reaction (NO3RR) offers a strategy for nitrogen cycle remediation and decentralized ammonia production, offering a potential alternative to the energy-intensive Haber-Bosch process. In this study, we employ PtPd bulk alloy single-crystal electrodes (Pt100-x...

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Detalles Bibliográficos
Autores: Jordá-Faus, Pepe, Feliu, Juan M., Herrero, Enrique, Arán-Ais, Rosa, Ferre Vilaplana, Adolfo|||0000-0002-9032-9015
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/226362
Acceso en línea:https://riunet.upv.es/handle/10251/226362
Access Level:acceso abierto
Palabra clave:Nitrate reduction
Nitric oxide reduction
Pt single crystals
PtPd bulk alloy single-crystals
Ammonia production
Descripción
Sumario:[EN] The electrochemical nitrate reduction reaction (NO3RR) offers a strategy for nitrogen cycle remediation and decentralized ammonia production, offering a potential alternative to the energy-intensive Haber-Bosch process. In this study, we employ PtPd bulk alloy single-crystal electrodes (Pt100-x Pd x (hkl)) to investigate how Pd incorporation influences NO3RR on well-defined Pt(111) and Pt(100) surfaces. By combining systematic electrochemical measurements with density functional theory (DFT) calculations, we uncover how Pd modulates surface reactivity and alters the reaction pathway. Our results show that Pd significantly enhances NO3RR activity, particularly on Pt(100), where Pt93Pd7(100) exhibits a 13-fold increase in current density compared to pure Pt(100). On Pt(111), Pd addition introduces a distinct reduction feature associated with nitric oxide adsorption at mixed Pt-Pd hollow sites, indicating a modified pathway that mitigates surface poisoning and promotes product desorption. DFT calculations further reveal that isolated Pd atoms embedded in the Pt(100) matrix stabilize nitrite adsorption and lower the activation barrier for nitrate reduction by approximately 0.15 eV. In contrast, excessive Pd content disrupts favorable adsorption geometries, leading to reduced catalytic performance. These findings highlight the critical role of atomic-scale surface composition and ensemble effects in tuning catalytic activity. This work provides fundamental insights into the design of bimetallic electrocatalysts for efficient and selective nitrate reduction, with broader implications for ammonia production and environmental remediation.