With the rapid availability of electricity generated from renewable energy resources, the desire to realize industrialized low-carbon hydrogen production through direct electrolysis of water is no longer an illusion. However, the requirements of traditional electrolysis technology for large amounts of freshwater electrolytes remain one of the great challenges. Seawater seems to be an ideal substitute for freshwater because of its abundant reserves. However, harsh requirements for electrocatalysts in seawater electrolysis significantly limit the wide application. Here, we report an efficient ternary-phase catalyst (W3P/WP/W) for hydrogen evolution reaction (HER). The metal-rich phosphide, W3P, reappears in our field of vision after more than 50 years through a more straightforward synthesis and acts as the main active phase in HER for the first time. W3P/WP/W outperforms most counterparts in pH-universal electrolytes. For freshwater electrolytes, it only requires 94 mV (acid condition) and 146 mV (alkaline condition) to attain a current density of 10 mA cm-2 with an extremely low mass loading. We use the natural seawater from LiaoNing Xinghai Bay for seawater study. In simulated seawater, the performance is comparable to commercial Pt/C; in KOH+seawater, only 0.966V and 1.441V of cell voltages are needed to reach current densities of 10 and 100 mA cm-2. Furthermore, ion exchange resin pretreatment method is used to meet the demands of proton exchange membrane (PEM) electrolyzers for neutral electrolytes. In this electrolyte, the current decay of the highly anti-toxic catalyst in continuous operation for 200 hours is almost negligible. The abundant vacancies, defects and the synergistic effect resulted in the outstanding performance. Consequently, the novel pH-universal electrocatalyst is promising for both freshwater and seawater electrolysis to realize large-scale green hydrogen production.

Ternary-phase nanostructure W3P/WP/W for high-performance pH-universal water/seawater electrolysis

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.