Abstract
Graphitic mesoporous carbon was modified with phosphorous heteroatoms in order to tune the catalytic selectivity and to investigate the roles of different oxygen species for the oxidative dehydrogenation reaction of isobutane to isobutene. Small changes in the isobutane apparent activation energy are consistent with the notion that the phosphorous groups do not change the nature of the active sites but they interfere with the availability of the sites. Our results show that the improvement on selectivity is not proportional to the amount of phosphorous added. Small phosphorous content improved the selectivity by suppressing the combustion of isobutane. However, a higher amount of phosphorous groups lead to coverage of selective quinone sites and/or creation of active sites favorable to total oxidation.
Original language | English |
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Pages (from-to) | 659-668 |
Number of pages | 10 |
Journal | Carbon |
Volume | 49 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2011 |
Funding
This research was supported by the Center for Nanophase Materials Sciences , which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. The research was supported in part by an appointment to the ORNL Postdoctoral Research Associates Program administered jointly by Oak Ridge Institute for Science and Education (ORISE) and ORNL.