Water provides an ideal source of pure hydrogen – abundant and free of harmful greenhouse gas byproducts. The electrolysis of water, or splitting water (H2O) into oxygen (O2) and hydrogen (H2), requires external electricity and an efficient catalyst to break chemical bonds while shifting around protons and electrons. To justify the effort, the amount of energy put into the reaction must be as small as possible while still exceeding the minimum required by thermodynamics, a figure associated with what is called overpotential.
For a catalyst to facilitate an efficient reaction, it must combine high durability, high catalytic activity, and high surface area. The strength of an element’s bond to hydrogen determines its reaction level – too weak, and there’s no activity; too strong, and the initial activity poisons the catalyst.
Platinum is the gold standard for electrocatalysis, combining low overpotential with high activity for the chemical reactions in water-splitting. But its high cost and other noble metals discourage widespread investment.
But researchers at Brookhaven National Laboratory have developed a new electrocatalyst (NiMoNx) that addresses one of these problems by generating hydrogen gas from water cleanly and with much more affordable materials. They said, it has a high-performing nanosheet structure and it could be a new model for generating hydrogen fuel from water in an inexpensive way and in terms of efficiency it is comparable to its platinum counter part.
The paper was published online May 8, 2012 in the journal Angewandte Chemie International Edition.