Ni-modified La2Ce2O7 oxygen carriers for chemical looping partial oxidation of methane

Chemical looping partial oxidation of methane (CLPOM) is an attractive approach for efficient production of syngas with a suitable H2/CO ratio. In this paper, the surface and bulk properties of La2Ce2O7 oxygen carrier were modified by NiO to promote its ability of methane activation and increase the availability of lattice oxygen. With the introduction of NiO, methane conversion increased by about three times compared to La2Ce2O7, with the H2/CO ratio remaining around 2. The doping effect on the structural characteristics was investigated by experimental characterization. The characterization results indicated that the surface Ni species promoted the activation of methane and its reaction with lattice oxygen while the bulk Ni species could weaken the strength of the Ce–O bond. This work illustrates that regulating the surface catalytic sites and bulk lattice oxygen availability of the oxygen carriers through doping is an effective strategy for modulating the CLPOM performance of oxygen carriers.