title: Mechanochemical synthesis of Au, Pd, Ru and Re nanoparticles with lignin as a bio-based reducing agent and stabilizing matrix.
abstract: A versatile, low-energy and solvent-free method to access nanoparticles (NPs) of four different transition metals, based on a bottom-up mechanochemical procedure involving milling of inorganic precursors, is presented. Lignin, a biomass waste, was used effectively as a reducing agent, for the first time in a mechanochemical context, to access MNPs where M = Au, Pd, Ru, Re. A series of metal precursors was used for this reaction and their nature was shown to be integral in determining whether NPs became incorporated within the organic lignin matrix, M@lignin, or not. Specifically, organometallic precursors resulted in extensive encapsulation of the NPs, as well as improved control over their size and shape, while ionic precursors afforded matrix-free NPs. The resulting NP-containing composites were characterized through Fourier-transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (PXRD). This mechanochemical grinding method for accessing M@lignin (M = Au, Pd, Ru and Re) is significantly more sustainable than the traditional solvent batch syntheses of metal NPs because it relies on the use of a biomass-based polymer, it is highly atom economical, it eliminates the need for solvents and it reduces drastically the energy input.
authors.affiliation: Centre for Green Chemistry and Catalysis, Department of Chemistry McGill University, 801 Sherbrooke St. W., H3A 0B8 Montreal, Canada. audrey.moores@mcgill.ca tomislav.friscic@mcgill.ca.
authors.forename: Monika J
authors.initials: MJ
authors.lastname: Rak
authors.forename: Tomislav
authors.initials: T
authors.lastname: Friščić
authors.forename: Audrey
authors.initials: A
authors.lastname: Moores
mesh_terms: D006046:Gold / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010165:Palladium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D019163:Reducing Agents / Q000737:chemistry*; D012211:Rhenium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D019163:Reducing Agents; D010165:Palladium; D012211:Rhenium; D006046:Gold; D012428:Ruthenium; D008031:Lignin