A Novel Solar System for Photothermal-Assisted Electrocatalytic Nitrate Reduction Reaction to Ammonia

Abstract

The traditional Haber-Bosch process for ammonia synthesis is plagued by high energy consumption, significant CO2 emissions. As a promising solution, solar photovoltaic electrocatalytic synthesis of ammonia has garnered significant attention. This study designed an electrocatalytic nitrite reduction system for ammonia production that employs solar photothermal-assisted and investigate the effects of different photovoltaic power supply voltage, heating temperatures, and flow velocities. The results demonstrate the system exhibited maximum ammonia production performance at 1.3 V under normal temperature conditions, resulting a maximum current density and ammonia production of 26 mA cm-2 and 1422.4 μg. Upon heating to 40 ℃, the maximum average current density of the system is 40 mA cm-2, and ammonia production is 2293 μg, representing 53.8% and 61.2% increasing in comparison to ambient temperatures. Although elevating the temperature to 60 ℃ led to increased average current density and ammonia production, the system's stability decreased to certain extent. Cyclic electrolysis conducted at 1.1 V and 40 ℃ for an hour revealed that ammonia production is 553.2 μg, 957.8 μg, 714.6 μg for flow rates of 10 mL/min, 20 mL/min, and 40 mL/min, respectively. These findings provide a reliable reference for implementing solar energy as a power source in ammonia synthesis.

Keywords: Ammonia production, Photovoltaic, Photothermal-Assisted, electrocatalytic