High Performance Chlorine Evolution in Saturated Nacl Solution by Protecting Metal Nano Activator

Abstract

Addressing the sluggish kinetics and corrosion of electrocatalysts in saturated NaCl solution is a pivotal yet challenging step toward improving the efficiency and sustainability of chlor−alkali industry. Herein, we have rationally developed an efficient Pt/RuO2−PO43− nanointerface heterojunction electrocatalyst, which exhibits excellent chlorine evolution reaction (ClER) performance in saturated NaCl solutions. Experimental studies show that Pt acts as an activator for RuO2, significantly enhancing the activity of RuO2. Surface modification of phosphate can inhibit the loss of the activator Pt and the amount of Pt dissolved in the unmodified phosphate catalyst was 12.3−fold higher than that in the modified phosphate catalyst. Density functional theory calculations indicate that PO43− can enhance the covalency of Pt-Pt bond and optimize the adsorption of Pt/RuO2 nanointerface for Cl intermediate, which can improve the electrocatalytic activity and durability. Additionally, the modification with phosphate can inhibit the catalyst's adsorption of the key intermediate *O in the oxygen evolution reaction, thereby reducing the occurrence of competitive reactions and increasing the selectivity. Together, by employing the Pt/RuO2@CNT−PO43− as electrocatalysts for ClER in a continuous−flow electrolytic cell, the device can achieve a current density of 500 mA cm−2 at a voltage of 1.56 V and achieve 98.5% Cl2 selectivity. Moreover, the continuous−flowing device can work stably over 100 hours under a fixed current density of 500 mA cm-2.

Keywords: ClER, modification, saturated, Heterojunction, continuous−flow