还原条件对NiFe_2O_(4-δ)结构稳定性及其催化分解CO_2活性的影响  

Effect of reduction condition on structure stability of NiFe_2O_(4-δ) and its catalytic performance of CO_2 decomposition

作　　者：傅毛生[1] 陈林深[2] 李建国[3] 陈诵英[4] 

机构地区：[1]南昌航空大学环境与化学工程学院,江西南昌330034 [2]浙江大学分析测试中心,浙江杭州310028 [3]江西省农业科学院环境影响评价中心,江西南昌330200 [4]浙江大学催化研究所,浙江杭州310028

出　　处：《燃料化学学报》2007年第4期431-435,共5页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(20277033);南昌航空大学科研基金课题

摘　　要：采用柠檬酸络合法制备NiFe2O4,运用XRD、DTA-TG等手段对其结构进行表征,并探讨还原条件对NiFe2O4-δ的结构稳定性及其催化分解CO2成C反应活性的影响。研究结果表明,由柠檬酸络合法制备的NiFe2O4样品量为0.5g时,利用H2还原制备氧缺位NiFe2O4-δ的最佳还原条件为还原温度320℃、氢气流量40mL/min、还原时间3h。还原温度过高、还原时间过长以及氢气流量过大,均会使NiFeO还原过度,尖晶石结构瓦解而转变成Fe(Ni)合金和α-Fe等。Nickel ferrite, NiFe2O4, with spinel structure was prepared by citrate coordination method. The samples were characterized by X-ray diffraction (XRD) thermal gravimetric analysis (TGA). When the weight of NiFe2O4 sample was 0.5 g, the optimum reduction condition for the preparation of oxygen-deficient nickel ferrite, NiFe2O4-δ, reduced by H2 was as follows: reduction temperature was 320°C, H2 flow rate was 40 mL&middotmin-1 and reduction time was 3 h. The results also showed that the higher reduction temperature and higher H2 flow rate as well as longer reduction time led to an excessive reduction of NiFe2O4-δ and the destructiveness of its spinel structure, resulting in the formation of Fe-Ni alloy Fe(Ni) as well as α-Fe phase. © 2007 Institute of Coal Chemistry, Chinese Academy of Sciences.

关 键 词：柠檬酸络合法 NiFe2O4-δ CO2分解 最佳还原条件 XRD 

分 类 号：O643.3[理学—物理化学] O614.81[理学—化学]