Abstract
The nature of the carbon deposits formed on an alumina-supported nickel catalyst have been characterized by their reactivity with H2 and H2O during temperature-programmed surface reaction (TPSR). Carbon deposits formed by exposure to hydrocarbons and carbon monoxide exhibit, depending primarily on the temperature during deposition, seven reactive carbon states during TPSR with 1-atm H2, including two very reactive states of chemisorbed carbon, a carbon film, nickel carbide, and two types of filamentary carbon. Filamentary carbon was identified by transmission and scanning electron microscopy, and Ni3C was identified from x-ray diffraction measurements. These results suggest that the deactivation of nickel catalysts is due to the accumulation of a carbonaceous film at low temperature, the rapid formation of filamentary carbon at moderate temperatures, and the formation of encapsulating carbon layers at very high temperature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
