H_2O_2催化氧化再生NiO的机理及动力学研究

Study on the Regeneration Mechanism and Kinetics of NiO by H_2O_2 Catalytic Oxidation

摘要利用红外光谱、扫描电镜及XRD分析了H202催化氧化吸附活性艳兰X-BR的NiO的再生机理，同时对其反应动力学进行了探讨。红外光谱分析表明，活性艳兰X-BR在发生降解的同时没有其他物质生成，Ni0表面降解较彻底；SEM图分析表明，新生态的Ni0具有疏松、颗粒分布均匀的特点，经再生后有一定程度板结，导致再生效率有所降低；XRD图显示，吸附前后及再生前后，Ni0的衍射峰没有发生较大改变，其稳定性较好。H202催化氧化NiO的动力学规律为：双氧水的反应是一级反应；活性艳兰X-BR的反应符合二级动力学方程；表观动力学模型r=-19．39exp[24．36×10^2／（RT）][H2O2]^1[CODcR]^2，同时反应的活化能Ea大约为24．36kJ／mol，该反应能够在常温下进行。

With IR absorption spectra, Scanning electron microscopy and XRD, the regeneration kinetics and mechanism of NiO by H202 catalytic oxidation are studied. The IR absorption spectra has shown that it doesn＇t have any other new organics under the degradation of reactive blue X-BR; SEM testing demonstrates that the morphology presents the loose and porous state of the new NiO, but some agglomerative structurec of the regenerated NiO which may result in reducing the regeneration efficiency. The XRD analyse indicates that no significant difference is observed for the strongest peak intensity of NiO＇s XRD spectra before and after the adsorption or regeneration, which means that NiO has no change. The kinetics of H2Oz catalytic oxidation reaction is described as first-order reaction, and the reaction of reactive blue X-BR is second-order. Its dynamics model is： r=- 19. 39exp[-24. 36 × 10^3/（RT）] [H2O2 ]^1 [CODcr]^2. The activation energy is 24. 36kJ/mol. The catalytic oxidation can react at normal temperature.