Coke deposition on platinum promoted WOx-ZrO2 during n-hexane isomerization

COMELLI, RA; CANAVESE, SA; QUERINI, CARLOS A; FIGOLI, NORA

APPLIED CATALYSIS A-GENERAL

ELSEVIER SCIENCE BV

Año: 1999 vol. 182 p. 275 - 283

0926-860X

Platinum on tungsten oxide promoted zirconia catalysts were prepared by calcining the zirconium hydroxide impregnated with tungsten species at different temperatures before platinum addition. Both the amount and nature of coke deposited on these catalysts during the n-hexane isomerization were studied. It was found that the amount of coke formed is small (<0.5%) over all samples. A similar type of coke was produced on catalysts calcined above 6008C, its amount showing a relationship with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. over all samples. A similar type of coke was produced on catalysts calcined above 6008C, its amount showing a relationship with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. over all samples. A similar type of coke was produced on catalysts calcined above 6008C, its amount showing a relationship with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. n-hexane isomerization were studied. It was found that the amount of coke formed is small (<0.5%) over all samples. A similar type of coke was produced on catalysts calcined above 6008C, its amount showing a relationship with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. 8C, its amount showing a relationship with the catalytic activity. The higher the speci®c rate, the larger the carbon content. A more hydrogenated and aliphatic coke was observed over the catalyst calcined at 5008C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. 8C, the difference being related to the properties of WOx±ZrO2 calcined at this temperature. The material calcined at 7008C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C. 8C before platinum addition reached the largest catalytic activity and a similar carbon content referred to the surface area than materials calcined at higher temperatures. Coke can be burnt out at 5008C.8C.