制备钙钛矿催化剂LaNiO_3用于染料废水的降解脱色

Preparation of perovskite catalyst LaNiO_3 for dye wastewater degradation and decoloration

为改善普通石墨电极的电催化性能,将以溶胶-凝胶法合成的钙钛矿氧化物LaNiO3混合其它原料做成气体扩散电极,用于电化学降解活性艳红X-3B,以脱色率来考核催化剂的氧还原活性.采用星点设计-效应面曲线法对催化剂制备工艺进行了优化,得出最佳工艺参数为:柠檬酸含量为金属离子物质的量的1.54倍,pH值为9.94,焙烧温度为824.39℃.采用X射线衍射(XRD)、动电位扫描等检测分析方法对所制备的催化剂进行表征和分析.结果表明,制备的催化剂晶相纯净、晶型完整、衍射峰强度较高,是较完整的钙钛矿结构;相比于普通石墨电极,掺杂催化剂的气体扩散电极极化阻力高,氧还原性能良好,有利于有机物的降解.

Perovskite oxide LaNiO3 was selected as a promoter for graphite electrode to enhance its electro-catalytic characteristics and LaNiO3 doped gas diffusion electrodes were made.Oxygen reduction activity of the prepared electrodes was investigated by using reactive brilliant red X-3B as a model pollutant.The parameters of preparing the catalyst by sol-gel method were studied in detail by Central Composite Design-Response Surface Methodology.As a result,the optimal conditions for the catalyst preparation were determined as follows： the mole ratio of citric acid to metal ions 1.54 ∶1,pH 9.94 and the calcination temperature 824.39 ℃.X-ray diffraction（XRD）,potentiodynamic polarization measurement were employed for the characterization and analysis of the catalyst.The results indicated that the catalyst had pure crystalling phase,high diffraction peak intensity,integrity and stable perovskite structure.The dynamic potential scanning curves indicated that LaNiO3 doped gas diffusion electrode had higher polarization resistance which was in favor of electro-chemical oxidation of organic pollutants.