Experimental study on the high performance of Zr doped LaCoO3 for solar thermochemical CO production

Abstract

Solar thermochemical CO production via CO2 splitting is an effective route to achieve carbon cycle and reduce carbon emissions. One of the most important issues for thermochemical fuel production technology is to find a material with high oxygen release capacity and fuel production as well as excellent thermal stability. Due to the excellent oxygen releasing capacity and limited fuel production and durability of LaCoO3, the feasibility of elemental doping for enhancing the redox capacity were studied in detail. Novel and high efficient redox materials, Zr doped LaCoO3 perovskites obtained were firstly used for solar thermochemical CO production. Zr doping is beneficial to improve CO yield and thermochemical redox stability. LaCo0.7Zr0.3O3, an optimum in doping for CO production, produced an average of 1066.6 μmol/g CO, which was an inspiring performance in the current perovskite based thermochemical field. The degree of reduction of LaCo0.7Zr0.3O3 was positively correlated with temperature and heating rate. Kinetics study shows that the activation energy of reduction reaction is 107.1 kJ/mol, which is much lower than that of CeO2, and the reduction process is a first order reaction. This material has better performances by comparison with CeO2 and other similar materials reported in literatures. The excellent CO production performance, pretty redox stability and kinetics manifested by LaCo0.7Zr0.3O3 provided a new approach for exploiting higher performing materials for solar thermochemical CO2 splitting.