Fabrication of carbon-based metal-free electrocatalyst for chlor-alkali process

Abstract

Chlorine (Cl2) gas is the most primary chemical precursor in many industrial manufacturing processes. For nearly half a century, the dimensional stable anode composed of RuO2 and TiO2 deposited on the Ti substrate has been widely used in the chlor-alkali process. However, the high cost, low product efficiency, and substrate passivation issues severely challenge the further commercialization of Cl2 production. Along with tremendous effort to reduce the precious metal load and develop non-precious metal to substitute the expensive and scarce Ruthenium-based mixed metal oxides, novel carbon-based electrocatalysts attracts considerable attention. Significant outbreaks have been achieved on metal-carbon hybrid electrocatalysts and demonstrated that carbon materials could be a promising CER candidate. Herein, we reported a rationally designed, abundantly N-doped carbon aerogel that could serve as a cost-effective metal-free electrocatalyst for efficiently electrocatalytic chloride oxidation. The electrocatalyst was synthesized through a facile, scalable, and environmental process, including freeze-drying the biomass-derived hydrogel and one-step calcination. The fabricated electrocatalyst exhibited excellent electrochemical performance with 295 mV to achieve 10 mA cm-2 and above 95% faradaic efficiency over 30 min, superior to the most transition metalbased electrocatalyst in CER. This work opens up a promising direction in the affordable and efficient chlor-alkali process.