Reduction of ion exchanged Pt2+ and Cu2+ ions with H2 forms metal atoms and protons of high Broensted acidity. The "coke" deposits formed during methylcyclopentane (MCP) conversion have been analyzed by temperature programmed oxidation (TPO). Acid sites are instrumental in ring enlargment of MCP; Cu atoms dilutePt ensembles required for ring opening. Coke deposits on metal and acid sites give rise to different TPO peaks, the high temperature peak increases with the concentration of Broensted sites. For high Cu/Pt ratios, coke formation on metal particles is negligible, showing that coke formation on metal surfaces is ensemble-specific.
EFFECTS OF ACIDITY AND METAL ENSEMBLE SIZE ON THE COKE FORMATION IN PT/NAY AND PTCU/NAY BY METHYLCYCLOPENTANE CONVERSION / Z., Zhang; Moretti, Giuliano; G. N., Alameddin; W. M. H., Sachtler. - STAMPA. - (1991), pp. 727-733. ((Intervento presentato al convegno 5TH INTERNATIONAL SYMP ON CATALYST DEACTIVATION tenutosi a EVANSTON, IL nel JUN 24-26, 1991.
EFFECTS OF ACIDITY AND METAL ENSEMBLE SIZE ON THE COKE FORMATION IN PT/NAY AND PTCU/NAY BY METHYLCYCLOPENTANE CONVERSION
MORETTI, GIULIANO;
1991
Abstract
Reduction of ion exchanged Pt2+ and Cu2+ ions with H2 forms metal atoms and protons of high Broensted acidity. The "coke" deposits formed during methylcyclopentane (MCP) conversion have been analyzed by temperature programmed oxidation (TPO). Acid sites are instrumental in ring enlargment of MCP; Cu atoms dilutePt ensembles required for ring opening. Coke deposits on metal and acid sites give rise to different TPO peaks, the high temperature peak increases with the concentration of Broensted sites. For high Cu/Pt ratios, coke formation on metal particles is negligible, showing that coke formation on metal surfaces is ensemble-specific.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
