铁酸铜尖晶石催化甲醛氧化的性能研究

通过溶胶-凝胶-自蔓延燃烧法制备了系列Cu_xFe_3-xO₄尖晶石催化剂。采用XRD和XPS表征方法对催化剂晶相结构及表面元素价态进行了分析,考察了Cu_xFe_3-xO₄催化甲醛的氧化效率。采用密度泛函理论探究了甲醛吸附在CuFe₂O₄表面的最稳定构型和吸附机理。结果表明,Cu_xFe_3-xO₄催化剂主要由Cu-Fe尖晶石相和部分CuO、Fe₂O₃相组成。Cu_0.5Fe_2.5O₄催化甲醛氧化效率最佳,在温度高于250℃时氧化效率达到90%以上。甲醛在CuFe₂O₄(100)表面的吸附属于化学吸附,吸附能为 -107.15 kJ/mol。

Formaldehyde Catalytic Oxidation Performance by Copper Ferrites Spinel-Type Catalyst

A series of Cu_xFe_3-xO₄ spinel-type catalysts were synthesized by sol-gel auto-combustion method. The crystal structure and surface chemical state of catalysts were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effect of reaction temperature on catalytic performance of Cu_xFe_3-xO₄ was investigated. Theoretical calculation based on density function theory (DFT) was performed to investigate formaldehyde adsorption over CuFe₂O₄(100) surface. Results demonstrated that the catalysts were mainly composed of spinel phase and several CuO, Fe₂O₃ phase. The Cu_0.5Fe_2.5O₄ catalyst exhibited over 90% oxidation efficiency when the reaction temperature was above 250℃. The adsorption of formaldehyde on the surface of CuFe₂O₄(100) was a chemical adsorption and the adsorption energy was -107.15 kJ/mol.