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

Journal Article

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.

• Magazine \ Newspaper: Catalysis