Effects of noble metals doped on mesoporous LaAlNi mixed oxide catalyst and identification of carbon deposit for reforming CH 4 with CO 2

BACKGROUND The effect of the B cation on the surface properties and catalytic activity in the dry reforming reaction over La 0. 4 M 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 (M=noble metal) perovskite‐type oxides with surface area 3.26–4.14 m 2 g –1 and rhombohedral structure was studied . RESULTS Among LaAl x Ni 1 ‐ x O 3 series, LaAl 0 . 2 Ni 0 . 8 O 3 had the highest catalytic activity, but suffered a slow deactivation with time‐on‐stream ( TOS ). It is observed that all samples presented similar activity at low reaction temperatures (500–600°C), while at higher temperatures (600–850°C) the prepared solid was more active and perovskite phase was transformed into Ni 0 or La 2 O 2 CO 3 . It was found that among the noble metal samples, La 0. 4 Rh 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 possessed the highest surface area and surface oxygen concentration and the best low‐temperature reducibility. For the Rh catalyst the CH 4 and CO 2 conversions were 89.1 and 86.2%, which were the most resistant against coke deposition and showed very high stability without decrease in reforming and remained constant during the 3000 min TOS . The following order of activity was observed: La 0. 4 Rh 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 > La 0. 4 Ru 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 > LaAl 0 . 2 Ni 0 . 8 O 3 > La 0. 4 Ir 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 ≥La 0. 4 Pt 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 > La 0. 4 Pd 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 . CONCLUSIONS It is believed that the high surface area and surface oxygen concentration and good low‐temperature reducibility were responsible for the good catalytic performance of the La 0. 4 Rh 0 . 6 Al 0 . 2 Ni 0 . 8 O 3 sample. © 2013 Society of Chemical Industry