Method of Synthesizing High-Efficiency Bifunctional Electrocatalysts

Abstract

University of Central Florida researchers have developed a method to produce efficient, cost-effective, and bifunctional (that is, anodic and cathodic) catalyst for water electrolysis applications. The new catalyst is a quarternary iron/nickel phosphoselenide nanoporous film (FeNi-PSe NF) with superior electrocatalytic properties that enable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).

Example applications include hydrogen and oxygen generation from alkaline solutions, deionized water, and seawater. Currently, hydrogen production results from steam methane reforming and coal gasification, demonstrating a heavy dependence on fossil fuels. The goal of shifting to large-scale hydrogen production is constrained by costly platinum group metal (PGM) catalysts.

With the invention, the researchers synthesized the NFs using electrochemical bottom-up (electrodeposition) and top-down (anodization) processes followed by a chemical vapor deposition (CVD) method. In the inventive group’s studies, the catalysts show an electrolysis efficiency of 69.7 percent, approximately 10 percent higher than other reported state-of-the-art catalysts.

Technical Details

The UCF invention is a method of synthesizing a bifunctional catalyst for water splitting applications. By modifying the electronic structure and composition of the catalyst, the method produces a self-supported quaternary iron/nickel phosphoselenide nanoporous film (FeNi-PSe NF). The slightly oxidized FeNi-Pse NF surface serves as an active site for oxygen evolution reactions, making hydrogen evolution reactions and oxygen evolution reactions well-balanced, thereby improving electrolysis efficiency.

The process of forming an iron-nickel-phosphorus nanofilm can comprise the following:

• Anodically converting an electrodeposited iron-nickel alloy film to an iron-nickel-oxygen nanofilm
• Thermally treating via phosphorization, the iron-nickel-oxygen nanofilm, and then
• Performing selenylation using chemical vapor deposition (CVD).

The selenium stabilizes the catalyst and improves its electrical conductivity. Multiple pores formed through the quaternary iron-nickel phosphoselenide nanoporous film improve the transportation of mass through the film.

In one example application, the FeNi-PSe NF works as an anode and a cathode in a two-electrode electrolytic cell. When the cell is subjected to a water source, such as seawater, the NF splits the water molecules in the water source. The hydrogen evolution reactions convert the water into hydrogen fuel that is usable as a renewable energy source.

Partnering Opportunity

The research team is looking for partners to develop the technology further for commercialization.

Stage of Development

Prototype available.

Benefit

Market Application