LaCoO_3载氧体在化学链燃烧中的性能研究

Performance of LaCoO_3 as Oxygen Carrier in Chemical-Looping Combustion Reaction

采用柠檬酸络合法制备了LaCoO_3氧化物,TPR表征结果表明该氧化物具有吸附氧和晶格氧,可以作为化学链燃烧的载氧体。化学链燃烧反应性能评价结果表明,以CO为燃料、反应温度为400℃和常压条件下,连续循环10次CO都全部转化,但是由于发生歧化反应,CO_2选择性没有达到100%。采用XRD,SEM和XPS等手段对新鲜LaCoO_3载氧体和循环10次后的LaCoO_3载氧体进行了表征,结果表明:连续循环10次后载氧体仍保持钙钛矿结构,由于钙钛矿氧化物具有丰富的吸附氧和晶格氧,所以载氧体保持了很好的稳定性。

LaCoO3 oxygen carrier was prepared by citric acid complex method, and its properties were characterized by temperature programmed reduction. The results showed that the oxygen carrier absorbed oxygen and lattice oxygen. The catalytic performances of the prepared sample were investigated in chemical-looping combustion of CO. The result showed that CO was conversed after 10 cycles at 400 ℃. However, selectivity of CO2 was not 100% due to disproportionation reaction. The characterization results of X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy showed that the oxygen carrier kept perovskite structure after 10 cycles. LaCoO3 absorbed oxygen and lattice oxygen abundantly, so it can keep high stability after ten cycles.