Abstract
The catalytic performances in the oxidation of propane of the AgMo 3 P 2 O 14 catalyst are quite good, leading to 70% of propene selectivity at 7% of propane conversion. We have checked that, before reaction, results of XANES and EXAFS obtained at the Mo K-edge (19999 eV) confirm those obtained by X-ray spectroscopy (oxidation state and Mo number of oxygen neighbour of 5.66, Mo=O bond length=1.72A). After reaction, we have shown that the catalyst is partially reduced (5.M→5.2), the number of oxygen atoms increases to 6 and the mean molybdenyl bond length decreases (1.68A) which is in agreement with the variation of this bend length with the oxidation state of the molybdenum in molybdenum phosphates. XPS measurements also confirmed a partial reduction of molybednum species and showed a migration of the silver cation to the surface, certainly participating to the surface stabilization. Moreover, a correlation between the catalytic activity and the modification of the catalyst is made showing that an equilibrium between Mo V and Mo VI species in the catalyst leading to the avrerage oxidation state of molybdenum of 5.2 seems to be very important.
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.
