摘要
Chemical looping dry reforming of methane(CL-DRM)is a highly efficient process that converts two major greenhouse gases(CH_(4)and CO_(2))into syngas ready for the feedstock of liquid fuel production.One of the major obstacles facing this technology now is creating oxygen carriers that are stable and reactive.We fabricated highperformance Sr_(0.98)Fe_(0.7)Co_(0.3)O_(3-δ)perovskite-structured oxygen carrier by combining A-site defects and B-site doping of SrFeO_(3-δ).During isothermal CL-DRM tests at 850℃,Sr_(0.98)Fe_(0.7)Co_(0.3)O_(3-δ)achieved 87%CH_(4)conversion and 94%CO selectivity in the CH_(4)partial oxidation reaction,followed by a syngas yield of 8.5 mmol/g,and CO yield of 4.2 mmol/g in CO_(2)decomposition.A-site defect engineering of the perovskite creates abundant oxygen vacancies and enhances oxygen storage capacity(OSC).Co-doping of the B-site of Sr_(0.98)FeO_(3-δ)increases oxygen mobility and CH_(4)/CO_(2)activation,resulting in high activity in the CL-DRM process.This methodology resulted in high ionic mobility and facilitated the rapid diffusion of oxygen in the bulk phase,thereby increasing the redox properties of SrFeO_(3-δ).The oxygen carrier exhibits excellent structural stability and regeneration ability in successive redox cycles.This strategy offers a simple but very effective pathway to tailor OSC,oxygen mobility,and oxygen vacancies of perovskite-structured materials for chemical looping or redox-involved processes.
基金
supported by the National Natural Science Foundation of China(Nos.52066007,52266007,and 22279048)
the Yunnan Major Scientific and Technological Projects(No.202202AG050017)
the Applied Basic Research Program of Yunnan Province(No.202101AT070076)。
