Revolutionary Electrodes Generate Hydrogen Fuel from Seawater

In a groundbreaking advancement, electrodes capable of generating hydrogen from seawater—without producing corrosive and hazardous chlorine gas—are set to be manufactured on a commercial scale for the first time.

As Doug Wicks, a representative from the US Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-E), states in a press release, “Conventional electrolysis has primarily relied on pure water, an increasingly scarce global commodity. These electrodes eliminate this dependency and instead utilize the ocean, which is the world’s most abundant water resource.”

The innovative process employs a negatively charged cathode and a positively charged anode to split seawater into four distinct “streams”: valuable hydrogen and oxygen, alongside innocuous acidic and alkaline byproducts that can be easily reintroduced to the ocean. Equatic, a California-based startup responsible for this technology, aims to market the resultant hydrogen and oxygen to help mitigate their operational costs.

This electrolysis occurs within a specially designed electrolyser, a device composed of electrode stacks that utilize electricity to dissociate water molecules. However, traditional systems often falter when addressing seawater, which contains dissolved salts, minerals, metals, and microorganisms detrimental to operational integrity. Moreover, the electric current that draws oxygen to the anode inadvertently splits salt, prompting the release of toxic chlorine gas that accelerates equipment deterioration.

To counteract this difficulty, Chen and his collaborators have crafted an anode that selectively extracts oxygen from water molecules while circumventing salt dissociation. This mechanism incorporates a chlorine-blocking layer, permitting water flow through the catalyst while impeding salt intrusion. Preliminary laboratory assessments indicate the anodes should endure a minimum of three years before necessitating maintenance or replacement.

Pau Farras, an academic at the University of Galway in Ireland who is unassociated with Equatic, emphasizes the potential of such oxygen-selective anodes for drawing hydrogen fuel from seawater, although he expresses the need for extensive field testing to validate their efficacy. “Real-world performance is essential for understanding their full capabilities,” he asserts.

The company is poised to commence production at a California facility capable of manufacturing 4,000 anodes annually. These components will be utilized in a demonstration plant in Singapore, designed to remove 10 tonnes of CO2 while producing 300 kilograms of hydrogen per day.