Size controlled copper nanoparticles hosted in mesoporous silica matrix: Preparation and characterization

A novel preparation strategy was performed to obtain uniform and size controlled, in a large scale, copper nanoparticles, hosted into mesoporous silica matrix. The method includes the initial deposition of finely dispersed copper nanoparticles, using a conventional incipient wetness impregnation of silica matrix with small amount of nitrate precursor and consecutive pretreatment in oxidation and reduction atmosphere. The further controlled growing of the loaded copper particles was performed in rotary bed reactor by step-wise deposition of copper over them by OMCVD techniques, using bis- (hexafluoroacetylacetonate) copper (II) hydrate as a precursor. A complex of physicochemical methods (TEM, Nitrogen physisorption, TPR and TPRD-MS measurements, UV-Vis and FTIR spectroscopy of adsorbed CO) was used for characterization of the samples. The catalytic properties of the obtained materials were investigated in methanol decomposition to CO and hydrogen. A mechanism of the copper particles growing was discussed. Size dependent effects of the redox and catalytic properties of the loaded copper particles which are strongly affected by their location in the silica porous structure are assumed.