Chemical
looping reforming of methane coupled with CO2 reduction
is a novel and useful route for methane conversion and
CO2 reduction. The choice of oxygen carrier with high reactivity
and strong resistance to carbon deposition is the key issue for this
process. In this study, a series of La
x
Ce1–x
Fe
x
Ni1–x
O3 oxides are
used as oxygen carriers. The doping amounts of Ce and Ni ions have
an influence on the reactivity of La
x
Ce1–x
Fe
x
Ni1–x
O3. The calcination temperature
also plays an important role in the performance of oxygen carrier
during the chemical looping process. With an increase of calcination
temperature, larger amounts of Ni species would immigrate to the surface
of La
x
Ce1–x
Fe
x
Ni1–x
O3 oxygen carrier. The amount of Ni species has
an effect on the formation of carbon deposition. During the successive
redox cycles, both La0.6Ce0.4Fe0.6Ni0.4O3-750 and La0.6Ce0.4Fe0.6Ni0.4O3-800 exhibit appropriate
H2/CO ratios near 2.0. The H2/CO molar ratios
of La0.6Ce0.4Fe0.6Ni0.4O3-850 and La0.6Ce0.4Fe0.6Ni0.4O3-900 increase sharply to much higher
values (>2.0) with the cycle number, indicating the formation of
carbon
deposition. The result demonstrates that the La0.6Ce0.4Fe0.6Ni0.4O3 oxygen carrier
calcined at lower temperature could enhance the resistance to carbon
deposition.