摘要
采用草酸共沉淀法制备了纳米ZnFe2O4粉体,分别用XRD,SEM,XPS等手段对所合成样品的相结构、微观形貌、表面元素状态进行了表征.固定床催化实验表明,ZnFe2O4催化剂具有较高的甲烷燃烧催化活性,甲烷起燃温度T10约为368℃.Fe 2p和O 1s XPS结果显示,催化剂表面含有部分Fe2+及相当可观的吸附氧物种,表明催化剂表面存在着大量氧空位.这些氧空位有利于气态氧分子在固体表面吸附并产生活性氧物种,可以在较低的温度使甲烷氧化.
Nano-ZnFe2O4 spinel particle was prepared by oxalic acid co-precipitation method.The structure,morphology and surface property of as-synthesized sample was characterized by XRD,SEM and XPS,respectively.The catalysis test result confirmed that the ZnFe2O4 has good catalytic activity for methane combustion with the methane light-off temperature T10≈368 ℃ in a fixed bed reactor.XPS results revealed that the excellent catalytic activity may be attributed to the surface oxygen vacancies arising from the peculiar inverse spinel structure with Oh site occupied by Fe2＋ and Zn2＋.
基金
国家自然科学基金(50442024)
安徽省教育厅自然科学基金(KJ2009A023Z)
安徽可控化学与材料化学工程重点实验室开放基金资助
