Synthesis of hollow and bimetallic gold and silver nanoshells for catalysis of oxidative amine coupling reactions

• Grant number: 18/23044-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2019
• End date: August 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Lucas Carvalho Veloso Rodrigues
• Grantee: Gabriela Ayres Martins Queiroz
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage, AP.TEM

Abstract

This project aims at the use of gold and silver nanoparticles (AuNP and AgNP, respectively) and of bimetallic and hollow nanospheres for oxidation reactions of amines to imines. Several nanostructures will be synthesized by simple, controlled synthetic routes capable of generating monodisperse and high yield nanoparticles. Au and AgNPs will be synthesized by the reduction of precursors of these metals and stabilized by steric or electrostatic repulsions. AgNPs will also be used as sacrificial metal for the galvanic replacement reaction with AuCl4 ions for the production of bimetallic gold and silver bimetallic shells. Both shape and composition will be controlled during the synthesis and shells with different thicknesses and Ag: Au ratios will be produced and all nanostructures will each be supported on commercial silicon dioxide. All steps of the syntheses will be characterized by UV-VIS, MEV and TEM and ICP-OES spectroscopy techniques. Finally all materials will be used as catalysts for oxidation reactions of amines to imines so that their catalytic efficiencies can be verified. The catalytic activity is expected to be enhanced by the synergism between both metals and also by increasing the surface area per unit volume of catalyst.