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 and significant CO2 emissions, leading to a noticeable environmental impact. 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 maximum ammonia production performance was achieved at 1.3 V under normal temperature conditions, resulting in a maximum current density and ammonia production rate of 26 mA cm−2 and 1422.4 μg, respectively. Upon heating to 40 °C, 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 °C 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 °C 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.