镧含量对铈镧合金氧化动力学的影响  

Effect of lanthanum on oxidation kinetics of cerium-lanthanum alloys

作　　者：王帅鹏 罗文华[1] 李赣[1] 李海波 WANG Shuai-peng;LUO Wen-hua;LI Gan;LI Hai-bo(Science and Technology on Surface Physics and Chemistry Laboratory,Mianyang 621907,China)

机构地区：[1]表面物理与化学重点实验室,四川绵阳621907

出　　处：《化学研究与应用》2018年第4期605-609,共5页Chemical Research and Application

基　　金：国家自然基金项目(11504344)

摘　　要：金属铈及其合金在催化剂和储氢材料等领域具有重要应用,而氧化腐蚀严重影响了其使用寿命和安全。本文利用热重分析法获得铈镧合金在低温条件下的氧化动力学曲线,结果表明镧的掺杂能够加速铈镧合金的氧化,且氧化速度随镧含量增加而逐渐加快。结合拉曼光谱综合分析推测:氧化初期阶段镧的掺杂能降低铈镧合金氧化活化能,从而加快其氧化进程;氧化中期阶段镧的掺杂能提高CeO_2氧化层中氧空位浓度,促进O^(2-)在氧化层中的扩散,从而加快铈镧合金氧化进程。Cerium alloy has great value of application in the catalyst and hydrogen storage materials.The oxidation corrosion can severely impact the lifetime and security of cerium alloy.The oxidation kinetics curves of cerium alloy was obtained under low temperature by thermogravimetry.The results indicate that the doping of lanthanum can accelerate the oxidation of cerium-lanthanum alloy,and the effect was increased with the lanthanum content.The result was confirmed by synthesis of thermogravimetry and Raman spectrum.The doped-lanthanum can accelerate the oxidation of cerium-lanthanum alloy by the reduction of oxidation activation energy in the first stage.The doped-lanthanum can accelerate the diffusion of O 2-in the oxide layer by increasing the concentration of oxygen vacancy,which can accelerate the oxidation of cerium-lanthanum alloy in the second stage.

关 键 词：铈镧合金 氧空位 镧含量 氧化动力学 

分 类 号：O643.1[理学—物理化学]