1. Laser synthesis, structure and chemical properties of colloidal nickel-molybdenum nanoparticles for the substitution of noble metals in heterogeneous catalysis
- Author
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Galina Marzun, Tanja Kallio, Stephan Barcikowski, Alexander Levish, Viktor Mackert, and Philipp Wagener
- Subjects
inorganic chemicals ,Oxide ,Chemie ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Heterogeneous catalysis ,01 natural sciences ,Catalysis ,Biomaterials ,Metal ,chemistry.chemical_compound ,NiMo ,Colloid and Surface Chemistry ,Alloys ,Organic chemistry ,Colloids ,Water splitting ,Hydrogen evolution ,ta116 ,Oxygen evolution ,021001 nanoscience & nanotechnology ,Laser ablation ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nickel ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Platinum - Abstract
Platinum and iridium are rare and expensive noble metals that are used as catalysts for different sectors including in heterogeneous chemical automotive emission catalysis and electrochemical energy conversion. Nickel and its alloys are promising materials to substitute noble metals. Nickel based materials are cost-effective with good availability and show comparable catalytic performances. The nickel-molybdenum system is a very interesting alternative to platinum in water electrolysis. We produced ligand-free nickel-molybdenum nanoparticles by laser ablation in water and acetone. Our results show that segregated particles were formed in water due to the oxidation of the metals. X-ray diffraction shows a significant change in the lattice parameter due to a diffusion of molybdenum atoms into the nickel lattice with increasing activity in the electrochemical oxygen evolution reaction. Even though the solubility of molecular oxygen in acetone is higher than in water, there were no oxides and a more homogeneous metal distribution in the particles in acetone as seen by TEM-EDX. This showed that dissolved molecular oxygen does not control oxide formation. Overall, the laser ablation of pressed micro particulate mixtures in liquids offers a combinational synthesis approach that allows the screening of alloy nanoparticles for catalytic testing and can convert micro-mixtures into nano-alloys.
- Published
- 2017