Ammonia is important for fertilizer manufacture and a chemical vector to produce a series of nitrogen-containing chemicals, such as nitric acid, organonitrogen compounds, urea, amino acid, etc. Meanwhile, NH₃ is a kind of clean energy carrier due to its high hydrogen content of 17.6 wt%, and NH₃ is easily liquified at ambient temperature (25 °C), showing great potential being as a H₂ provider in fuel cells. However, current industrial NH₃ production exclusively relies on the Haber–Bosch process driven by fossil fuels, which consumes ≈ 1-2 % global energy consumption and ≈ 1.5 % CO₂ emission worldwide [1].

In this study, the aim is to develop photoelectrochemical methods and design suitable reactors for producing ammonia in ambient conditions. Since nitrogen and nitrate reduction are multi-electron transfer processes, and the catalysts designed for one can often be adapted or optimized for the other, research on electrocatalysts for nitrate reduction helps in understanding the performance and selectivity of materials, which is crucial for improving nitrogen reduction technologies.

Based on earlier work of Liu et.al., nitrate effectively converted to ammonia in a simple H-cell using the copper-nickel alloy catalysts, and this series of experiments showed reliable production rate and faradaic efficiency [2]. A reactor is designed to perform nitrate reduction experiments under flow conditions in two detachable champers with commercially available electrodes. The production rate, faradaic efficiency and the total amount of ammonia produced as reported by Liu in the batch system, and this research in both batch and continuous operation mode were studied.

The studies revealed that the efficiency of deposited electrodes varies. To address this, a separate study was conducted to investigate the impact of different filament materials used to manufacture the electrode scaffold, its influence on the deposition process and their subsequent effect on nitrate conversion. As manufacturers do not provide detailed information on the chemical properties of the filaments, empirical testing is essential to determine the most suitable material.

Ammonia detection is conventionally performed using the indophenol method in a batch, offline system, requiring approximately 2.5 hours per sample, including preparation steps. This study aims to enhance the efficiency and accessibility of ammonia detection by integrating self-fabricated 3D-printed syringe pumps with a reactor designed to heat the reactants, thereby reducing analysis time and simplifying the process [3].