Gasification characteristics of carbon species derived from model reforming compound over Ni/Ce–Zr–O catalysts

• TGA coupled with FT-IR, MS and SEM techniques are used.
• Carbon species deposited over 10% Ni/CZO from isooctane decomposition used as the model compounds.
• Complete gasification of coating carbon observed at low temperatures around 600 °C.
• Gasification of filamentous carbon species depending on its formation temperature.

This work addresses a thermogravimetric method for the steam gasification of carbon deposited over ceria–zirconia supported nickel (10% Ni/CZO) catalysts. The carbon deposits, which were obtained from the decomposition of isooctane over 10% Ni/CZO catalyst at 500, 650, and 725 °C, respectively, were used as the model species. Gasification temperature and characteristics of different carbon species have been investigated, and the resulting gaseous products were measured by FT-IR spectroscopy and mass spectroscopy. The carbon species formed at different decomposition temperatures indicated distinctly different ability for gasification. Combined with features of TPO profiles and SEM images, our experiments suggest that the coating carbon, which covers the surface of Ni/CZO catalyst, can be removed by gasification at low temperatures around 600 °C. However, the gasification degree of filamentous carbon species depends on its formation temperature. For filamentous carbon obtained from isooctane decomposition at 500 °C the gasification starts at 690 °C, while filamentous carbon species obtained from isooctane decomposition at temperatures ≥650 °C undergo complete gasification at this temperature.

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