Highly-efficient natural gas desulfurization and simultaneous HO synthesis based on the electrochemical coupling reaction strategy.

Hydrogen sulfide (HS) generated by natural gas exploitation is a dangerous and harmful gas that needs to be purified. Electrochemical Natural Gas Desulfurization offers a promising way for HS purification and resource utilization in ambient conditions. However, poor energy efficiency and low resource value limit the prospective application in the industry. Herein, we propose a gas-liquid flow electrocatalysis system that couples HS oxidation and O reduction processes to effectively recover sulfur and HO with low energy consumption. Gas diffusion and mass transfer are accelerated by gas-liquid flow cells, which also significantly decrease the resistance. Besides, I/I redox pairs promote selective HS oxidation while inhibiting water decomposition, resulting in a 56% reduction in oxidation potential. Moreover, the surface proton concentration is elevated by employing a modified carbon gas diffusion electrode (GDE), which assists to maintains a high HO faradic efficiency. The system is able to operate at a high current density of 102 mA/cm at an E voltage of 3.5 V, yielding S and HO at rates of 60 mg cm h and 50 mg cm h respectively. A techno-economic model forecasts the effects of system efficiency and energy prices on operational costs and illustrates potential routes to a plant-gate levelized application in the petrochemical industry.