Hydrogen has drawn attention in recent years as a potential source of clean energy because it burns without producing climate-damaging emissions. However, traditional hydrogen production methods have a substantial carbon footprint, and cleaner methods are expensive and technically complex.
Credit: Pixabay/CC0 Public Domain Now researchers are reporting a significant advance, a two-electrode catalyst that relies on one compound to efficiently produce hydrogen and oxygen from both seawater and freshwater. Previous attempts at such bi-functional catalysts to split water into hydrogen and oxygen have generally resulted in poor performance in one of the two functions. Using two separate catalysts works but increases the catalysts' manufacturing cost. In work described in Energy & Environmental Science, researchers from the University of Houston, the Chinese University of Hong Kong and Central China Normal University report using a nickel/molybdenum/nitrogen compound, tweaked with a small amount of iron and grown on nickel foam to efficiently produce hydrogen and then, through a process of electrochemical reconstruction sparked by cycling voltage, converted to a compound that produced a similarly powerful oxygen evolution reaction. The researchers said using a single compound for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER)—albeit slightly changed through the reconstruction process—not only makes water splitting more affordable, it also simplifies the engineering challenges. Most materials are best suited for either HER or OER, but both reactions are required to complete the chemical reaction and produce hydrogen from water. Zhifeng Ren, director of the Texas Center for Superconductivity at UH and a corresponding author for the paper, said…