Juliana Jumadi, Ihsan Naiman Ibrahim, Kumaran Kadirgama, Lingenthiran Samylingam, Navid Aslfattahi, Muhammad Hafidz Fazli Md Fauadi, Wan Sharuzi Wan Harun
The removal of nitrogen species, particularly nitrates, is critically important for environmental remediation and the production of renewable energy. Converting nitrogen in wastewater into ammonia is an alternative to the Haber-Bosch process, which constitutes an effective and economical method for addressing nitrate contamination in source waters. This process simultaneously facilitates the reclamation of nitrogen as a renewable and promising energy resource. This approach not only decreases dependence on energy-consuming procedures but is also environmentally friendly. Copper-based electrocatalysts for the nitrogen/nitrate reduction reaction (NRR) have been widely studied, yet a comprehensive understanding of the relationships between their preparation, characterization, and catalytic activity remains incomplete. In this review, we aim to provide a structured summary of synthetic approaches for Cu-based electrodes using both physical and chemical methods, highlighting the structure–activity correlations between synthesis strategies and catalyst performance. We also present a thorough overview of advanced characterization techniques, including structural, morphological, compositional, electrochemical, and in situ/operando studies, to identify active sites, reaction intermediates, and degradation pathways. The electrocatalytic performance of Cu-based electrodes in NRR is critically analyzed and compared, with emphasis on the effects of morphology, surface composition, electrolyte selection, and pH on activity and selectivity. Methods for quantifying ammonia, such as colorimetry, NMR, GC, and ion chromatography, are reviewed to ensure benchmarking and reproducibility. Despite these advances, practical application remains limited due to challenges such as the trade-off between selectivity and activity, catalytic deactivation, and competition from the hydrogen evolution reaction (HER). This work aims to provide a consistent and rational framework for screening Cu-based systems toward highly efficient and cost-effective ammonia electrosynthesis. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.
Automotive Engineering Centre, Universiti Malaysia Pahang Al-Sultan Abdullah, Pahang, Pekan, 26600, Malaysia; Faculty of Mechanical and Automotive Engineering Technology, Universiti Malaysia Pahang Al-Sultan Abdullah, Pahang, Pekan, 26600, Malaysia; Centre for Advanced Mechanical and Green Technology, Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, Melaka, 75450, Malaysia; Institute of Fluid Dynamics and Thermodynamics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, Prague, 166 07, Czech Republic; Faculty of Artificial Intelligence and Cybersecurity, Universiti Teknikal Malaysia Melaka, Melaka, DurianTunggal, Malaysia; Department of Mechanical Engineering, Galgotias University, Uttar Pradesh, Greater Noida, 203201, India; Department of Mechanical Engineering, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Jakarta, 13220, Indonesia
Research at a Glance
Register to unlock
Topics & SDG Alignment
Register to unlock
Collaboration
Register to unlock
Author Profile (Selected)
Register to unlock
References Overview
Register to unlock
Journal & Source
Register to unlock
Metadata & Integrity
Register to unlock