Delsarte, Stéphanie
[UCL]
Serin, V
Flank, AM
Villain, F
Grange, Paul
[UCL]
Amorphous nitrided galloaluminophosphates "AlGaPON" catalysts with nitrogen contents varying from 0 to 23.3 wt% N were obtained by nitriding an Al0.5Ga0.5PO4 precursor under ammonia flow at 750degreesC in a tubular furnace. The structural changes induced by this treatment were investigated by electron energy loss spectroscopy (EELS), X-ray absorption spectroscopy (XAS), and X-ray photoelecton spectroscopy (XPS). XANES and XPS results indicate that the first-coordination spheres of P, Ga, and Al atoms are modified by nitridation. In particular, the comparison of the P XANES spectra recorded on "AlGaPON" and on a PON phosphorus oxynitride (reference of mixed PO2,N-2, tetrahedra) reveals that mainly PO2,N-2, tetrahedra are present in highly nitrided samples. Moreover, the replacement of oxygen by nitrogen probably concerned P-O-Ga bonds rather than P-O-Al. EELS investigation reveals that the precursor is homogeneous at the used probe scale, but indicates that nitridation is accompanied by a loss of homogeneity of the material. (C) 2002 Elsevier Science.
Bibliographic reference |
Delsarte, Stéphanie ; Serin, V ; Flank, AM ; Villain, F ; Grange, Paul. Structural investigation of mixed nitrided galloaluminophosphates "AlGaPON"' by EELS, XAS, and XPS spectroscopies. In: Journal of Solid State Chemistry, Vol. 163, no. 1, p. 163-177 (2002) |
Permanent URL |
http://hdl.handle.net/2078.1/42165 |