Gallium-promoted Ni catalyst supported on MCM-41 for dry reforming of methane

مقال فى مجلة

2018

A novel approach to the in situ regeneration of a spent alumina-supported cobalt–iron
catalyst for catalytic methane decomposition is reported in this work. The spent catalyst was
obtained after testing fresh catalyst in catalytic methane decomposition reaction during 90 min.
The regeneration evaluated the effect of forced periodic cycling; the cycles of regeneration were
performed in situ at 700 C under diluted O2 gasifying agent (10% O2/N2), followed by inert
treatment under N2. The obtained regenerated catalysts at different cycles were tested again in
catalytic methane decomposition reaction. Fresh, spent, and spent/regenerated materials were
characterized using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), laser
Raman spectroscopy (LRS), N2-physisorption, H2-temperature programmed reduction (H2-TPR),
thermogravimetric analysis (TGA), and atomic absorption spectroscopy (AAS). The comparison
of transmission electron microscope and X-ray powder diffraction characterizations of spent and
spent/regenerated catalysts showed the formation of a significant amount of carbon on the surface
with a densification of catalyst particles after each catalytic methane decomposition reaction preceded
by regeneration. The activity results confirm that the methane decomposition after regeneration cycles
leads to a permanent deactivation of catalysts certainly provoked by the coke deposition. Indeed, it is
likely that some active iron sites cannot be regenerated totally despite the forced periodic cycling.

• مجلة/صحيفة: Catalysis