Anti-precipitation molecular metal chalcogenide complexes modification for efficient direct alkaline seawater splitting at the large current density

Abstract

Hydrogen production from direct alkaline seawater electrolysis at large current density is a key technology for marine energy projects. However, catalyst poisoning due to insoluble precipitation is a key issue that should be addressed. In this work, we used Pt/CNT electrocatalysts modified with molecular metal chalcogenide complexes. During the direct electrolysis of alkaline seawater, the modified Pt/CNT electrocatalyst can effectively reduce the formation of insoluble precipitates on the cathode surface, which is conducive to the stable operation of the hydrogen evolution reaction. Theoretical simulations and in situ experiments both demonstrate that the modified Pt/CNT was affected by the coordination to form coordination compounds, which effectively prevented the formation of insoluble precipitates. The alkaline anion exchange membrane (AEM) electrolyzer with a modified Pt/CNT electrocatalyst exhibited an industrially required current density of 1.0 A cm−2 at 2.0 V and 60 °C, achieving long-term stability in excess of 600 h.