Supported Rh particles obtained by reduction in H2 of severely calcined Rh/Mg/Al hydrotalcite-type phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at r.t. and nominal liquid N2 temperature) and transmission electron microscopy. The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750 to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbes at r.t., CO dispropornation occurs on Rh and it accompanies the formation of Rh(I)(CO)2. The role of interlayer anions in the HT precursors to affect the properties in the final materials has been investigated considering samples prepared from silicate- instead carbonate-containing precursors.
In situ characterization of CO interacting with Rh nanoparticles obtained by calcination and reduction of hydrotalcite-type precursors / F. Basile; I. Bersani; P. Del Gallo; S. Fiorilli; G. Fornasari; D. Gary; R. Morterra; B. Onida; A. Vaccari. - In: INTERNATIONAL JOURNAL OF SPECTROSCOPY. - ISSN 1687-9449. - ELETTRONICO. - 2011:(2011), pp. 1-8. [10.1155/2011/458089]
In situ characterization of CO interacting with Rh nanoparticles obtained by calcination and reduction of hydrotalcite-type precursors
BASILE, FRANCESCO;BERSANI, IRENE;FORNASARI, GIUSEPPE;VACCARI, ANGELO
2011
Abstract
Supported Rh particles obtained by reduction in H2 of severely calcined Rh/Mg/Al hydrotalcite-type phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at r.t. and nominal liquid N2 temperature) and transmission electron microscopy. The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750 to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbes at r.t., CO dispropornation occurs on Rh and it accompanies the formation of Rh(I)(CO)2. The role of interlayer anions in the HT precursors to affect the properties in the final materials has been investigated considering samples prepared from silicate- instead carbonate-containing precursors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
