固相反应法制备的草酸铁水合物的热分解动力学  

Thermal Decomposition Kinetics of Fe_2(C_2O_4)_3·5H_2O Prepared by Solid-State Reaction

作　　者：胡天麒[1] 冯宇[1] 蒲昭廷 武蒙蒙[1] 米杰[1] 

机构地区：[1]太原理工大学煤科学与技术教育部和山西省重点实验室,太原030024

出　　处：《太原理工大学学报》2015年第5期520-525,共6页Journal of Taiyuan University of Technology

基　　金：国家自然科学基金资助项目:微波固相合成复合金属氧化物中高温煤气脱硫材料及其性能研究(51272170;21276172)

摘　　要：以H2C2O4·2H2O和Fe(NO3)3·9H2O为原料,采用室温固相反应法合成草酸铁水合物。通过TG-DTG/DSC在空气气氛中详细研究了草酸铁水合物的热分解过程,采用X-射线衍射、扫描电镜和傅里叶变换红外光谱技术对草酸铁水合物及其分解产物进行了表征。实验结果表明,草酸铁水合物的热分解过程分为三个阶段,最终的分解产物为α-Fe2O3。通过Ozawa积分法和Coats-Redfern积分法来判定草酸铁水合物热分解过程第二阶段的动力学模型函数,并求算其热分解动力学参数,得出在动态空气气氛中,草酸铁分解过程遵循随机成核与随后生长模型,其积分表达式为G(α)=[-ln(1-α)]1/2,活化能为(102.7±5.6)kJ/mol。The thermal decomposition of Fe2（C2O4）3 ·5H2O ,which was synthesized by solid state reaction using H2 C2 O4 · 2H2 O and Fe（NO3 ）3 · 9H2 O as raw materials ,was investigated in dynamic air atmosphere using TG‐DTG/DSC .X‐ray powder diffraction ,scanning electronic mi‐croscopy and fourier transform‐infrared spectroscopy were used to characterize the structure of Fe2 （C2 O4 ）3 · 5H2 O and its decomposition product .The results indicate that the decomposition proceeds through three well‐defined steps and the final decomposition product of Fe2 （C2 O4 ）3 · 5H2 O was nanostructured α‐Fe2 O3 .The kinetic model and kinetic parameters of the second de‐composition stage of Fe2 （C2 O4 ）3 · 5H2 O were determined by the comparison of the integral methods of Ozawa and Coats‐Redfern .Data analysis indicated that the decomposition reactions are best described by the solid‐state nucleation‐grow th mechanism .T he activation energy and the ki‐netic mechanism function are determined to be （102.7 ± 5.6） kJ/mol and G（α）= [-ln（1-α）]1/2 , respectively .

关 键 词：固相反应 草酸铁 热分解动力学 Ozawa积分法 Coats—Redfern积分法 纳米Fe2O3 

分 类 号：O643[理学—物理化学]