Polyvinylalcohol (PVA)-stabilised Au nanoparticles (NPs) were synthesized by colloidal methods, in which temperature variations (−75 to 75°C) and mixed H2O/EtOH solvent ratios (0, 50 and 100 vol:vol) were used. The resulting Au NPs were immobilized on TiO2 (P25) and their catalytic performance was investigated for the liquid phase oxidation of glycerol. There was a systematic increase in average Au particle size as the temperature of colloidal preparation increases, for each unique solvent system. Generation of the Au NPs in H2O at 1°C resulted in a high observed activity compared to current Au/TiO2 catalysts (TOF = 915 h-1). Interestingly, Au catalysts with similar average particle sizes but prepared under different conditions had contrasting catalytic performance. For the most active catalyst, aberration-corrected HAADF STEM analysis identified the presence of isolated ultra small Au clusters (from 1-5 atoms) for the first time using a modified colloidal method, which was supported by experimental and computational CO adsorption studies. It is proposed that the variations in the populations of these species, in combination with other solvent/PVA effects, is responsible for the contrasting catalytic properties.
Tailoring gold nanoparticle characteristics and the impact on aqueous-phase oxidation of glycerol / S. M. Rogers, C. R. A. Catlow, C. E. Chan-Thaw, D. Gianolio, E. K. Gibson, A. Gould, N. Jian, A. J. Logsdail, R. E. Palmer, L. Prati, N. Dimitratos, A. Villa, P. P. Wells. - In: ACS CATALYSIS. - ISSN 2155-5435. - 5:7(2015), pp. 4377-4384.
|Titolo:||Tailoring gold nanoparticle characteristics and the impact on aqueous-phase oxidation of glycerol|
VILLA, ALBERTO (Penultimo)
|Parole Chiave:||aberration-corrected TEM; colloids; glycerol oxidation; gold nanoparticles; heterogeneous catalysis; XAFS|
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
Settore CHIM/02 - Chimica Fisica
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/acscatal.5b00754|
|Appare nelle tipologie:||01 - Articolo su periodico|