Methane catalytic reforming by carbon dioxide on Mg–Al oxides prepared by hydrotalcite route with different surfactants (CTAB, glucose, P123) or with intercalation of SBA-15 and impregnated by nickel

Abstract

Four magnesium–aluminum mixed oxides were synthesized by the hydrotalcite route using four modifying agents (three surfactants: glucose, CTAB, and P123, as well as silica SBA-15), and then calcined at 550 °C. Physicochemical characterizations were conducted before and after calcination. X-ray diffraction (XRD), differential thermal and gravimetric analyses (DTA/TGA), and Fourier Transform Infrared Spectroscopy (FTIR) showed that the hydrotalcite structure was obtained even in the presence of a modifying agent. This structure was converted into mixed oxides upon calcination where the pore size distribution was more homogeneous in the presence of a modifying agent. Nickel was impregnated on these oxides and then the catalytic performances of the obtained catalysts were tested in the dry reforming of methane as a model for biogas reforming. In our conditions, the catalyst based on SBA-15 did not show any catalytic activity whereas good catalytic activities and high carbon balances were obtained for the samples prepared with the three surfactants. The effect of a surfactant is mainly the slight enhancement of the carbon balance due to higher nickel species dispersion. It is suggested to put into evidence this slight enhancement by time on stream studies, where the formation of a lower amount of carbon and longer lifetime for catalysts elaborated with surfactants is expected.

Keywords

• Dry reforming
• Mg–Al hydrotalcite
• Methane
• Nickel
• SBA-15
• Surfactants