Photochemical Route for Accessing Amorphous Metal Oxide Materials for Water Oxidation Catalysis

• Published in: Science (American Association for the Advancement of Science) 2013-04, Vol.340 (6128), p.60-63
• Main Authors: Smith, Rodney D. L., Prévot, Mathieu S., Fagan, Randal D., Zhang, Zhipan, Sedach, Pavel A., Siu, Man Kit Jack, Trudel, Simon, Berlinguette, Curtis P.
• Format: Article
• Language: English
• Subjects: Amorphous materials; Catalysis; Catalysts; Catalytic oxidation; Chemical Sciences; Chemistry; Current density; Decomposition reactions; Electrochemistry; Electrodes; Exact sciences and technology; General and physical chemistry; Hematite; Kinetics and mechanism of reactions; Material films; Metal oxides; Metals; Nickel; Noble metals; Oxidation; Oxides; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Reaction kinetics; Renewable resources; Thin films; Water; X ray film
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1233638

Large-scale electrolysis of water for hydrogen generation requires better catalysts to lower the kinetic barriers associated with the oxygen evolution reaction (OER). Although most OER catalysts are based on crystalline mixed-metal oxides, high activities can also be achieved with amorphous phases. Methods for producing amorphous materials, however, are not typically amenable to mixed-metal compositions. We demonstrate that a low-temperature process, photochemical metal-organic deposition, can produce amorphous (mixed) metal oxide films for OER catalysis. The films contain a homogeneous distribution of metals with compositions that can be accurately controlled. The catalytic properties of amorphous iron oxide prepared with this technique are superior to those of hematite, whereas the catalytic properties of α-Fe₁₀₀ -y-z Co y Ni z O x are comparable to those of noble metal oxide catalysts currently used in commercial electrolyzers.