| dc.creator | Reyes,P. | |
| dc.creator | Aguirre,M del C | |
| dc.creator | Melián-Cabrera,I. | |
| dc.creator | López Granados,M. | |
| dc.creator | Fierro,J. L. G. | |
| dc.date | 2002-12-01 | |
| dc.date.accessioned | 2017-03-07T16:17:12Z | |
| dc.date.available | 2017-03-07T16:17:12Z | |
| dc.identifier | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0366-16442002000400027 | |
| dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/399041 | |
| dc.description | The surface and catalytic properties in the vapor-phase hydrogenation of crotonaldehyde on Rh/TiO2 has been studied. It was found that a partial reduction of the support produces a surface decoration of the metal component. Thus, interfacial sites are created, which are responsible of an increase in the selectivity to crotyl alcohol, via enhancement of the polarization of the C=O bond. Photoelectron spectra revelead that rhodium is in different oxidation states, with a contribution of ca. 20 % Rhd + and 80 % Rhº species for LTR catalyst and only a slight increase of Rhd + for HTR catalyst. TEM studies revelead that Rh has metal particle size close 3 nm with small increases in the catalyst reduced at high temperature. DRIFTS essayed carried out under reaction conditions allowed to identify crotonaldehyde species strongly adsorbed through the C=C bond and weakly coordinated through both the C=C and C=O bonds. After reduction at 723 K an increase in the peak at 1660 cm-1 ascribed to an interaction between the carbonyl group and the surface, was observed. This peak seems to be stabilized at interfacial Rh/TiOx sites The deactivation in crotyl alcohol formation can be ascribed to the generation of strongly chemisorbed asymmetric carboxylate species detected by band at 1740 cm-1. This band grows at expense of crotonaldehyde O s - bonded intermediate chemisorbed on coordinatively unsaturated sites (Lewis acid sites) responsible of the crotyl alcohol obtaintion (detected by a band at 1653 cm-1). Additionally, a small band at 2068 cm-1 assigned to CO adsorbed on transition metals, which increases with time on-stream may explain the deactivation of the catalysts in flow systems. | |
| dc.format | text/html | |
| dc.language | en | |
| dc.publisher | Sociedad Chilena de Química | |
| dc.source | Boletín de la Sociedad Chilena de Química v.47 n.4 2002 | |
| dc.subject | Rh/TiO2 | |
| dc.subject | crotonaldehyde hydrogenation | |
| dc.subject | DRIFTS | |
| dc.title | Crotonaldehyde Hydrogenation on Rh/TiO2 catalysts: In situ DRIFTS studies | |
| dc.type | Artículos de revistas | |
