The search for methods capable of generating transition metal nanocatalysts stable in water is a major challenge catalytic. The mastery of these methods allows the development of new catalytic materials for greater efficiency in terms of selectivity and activity, allowing lower waste generation. The development of new methods for catalytic oxidation of organic molecules is of significant interest in the development of sustainable chemical synthesis approaches. The selective oxidation of alcohols is an important process for the synthesis of intermediates and products used in the manufacture of many materials. This project aims at developing bimetallic nanoparticles composed mainly of Ag, Au, Cu, Pd and Pt, with well defined geometries and sizes, as catalysts in processes of selective oxidation of alcohols. Such nanoparticles combine plasmonic and catalytic properties. The catalytic performance of the bimetallic nanoparticles will be studied in the model reaction of oxidation of cinnamyl alcohol with oxygen in water. Systematic spectroscopic studies of the interaction processes between the substrates to be oxidized and the catalyst surface, as well as intermediates and products should also be developed, with particular emphasis on the use of surface enhanced Raman spectroscopy (SERS) The proposed approach uses Ag and Cu colloidal metal nanoparticles of - in cubes, sticks, wires and triangles - as sacrificial templates in the construction of multi-metal nanocatalysts. To obtain the nanocatalysts, a galvanic reaction will be used, where the metal center of (Ag or Cu) has a smaller reduction potential than the outer layer of metal (Au, Pd and Pt), leading to the formation of porous structures of the alloy or nanoshell types with the hollow interior, and therefore with high surface area. Systematic studies of the nanostructures by spectroscopic techniques, microscopy and X-ray diffraction will be carried out. By controlling the proportions of metals in the nanostructure, correlations betwee morphology, size and chemical composition of the nanostructures with their catalytic activity will be investigated.
News published in Agência FAPESP Newsletter about the scholarship: