Promoting Efficient Ruthenium Sites With Lewis Acid Oxide for the Accelerated Hydrogen and Chlor-Alkali Co-Production

Abstract

Ruthenium (Ru) –based catalysts have been considered a promising candidate for efficient sustainable hydrogen and chlor-alkali co-production. Theoretical calculations have disclosed that the hollow sites on the Ru surface have strong adsorption energies of H and Cl species, which inevitably leads to poor activity for cathodic hydrogen evolution reaction (HER) and anodic chlorine evolution reaction (CER), respectively. Furthermore, it have confirmed that anchoring Lewis acid oxide nanoparticles such as MgO on the Ru surface can induce the formation of the onion-like charge distribution of Ru atoms around MgO nanoparticles, thereby exposing the Ru-bridge sites at the interface as excellent H and Cl adsorption sites to accelerate both HER and CER. Under the guidance of theoretical calculations, a novel dispersed MgO nanoparticles on Ru (MgO_x-Ru) electrocatalyst is successfully prepared. In strongly alkaline and saline media, MgO_x-Ru recorded excellent HER and CER electrocatalytic activity with a very low overpotential of 19 mV and 74 mV at the current density of 10 mA cm⁻², respectively. More stirringly, the electrochemical test with MgO_x-Ru as both anodic and cathodic electrodes under simulated chlor-alkali electrolysis conditions demonstrated superior electrocatalytic performance to the industrial catalysts of commercial 20 wt% Pt/C and dimensionally stable anode (DSA).