A series of Co/TiO2 catalysts were prepared by incipient wetness impregnation. The pH value of the impregnation solution was adjusted by using nitric acid and urea. The XRD, TPR and XPS characterization results indica...A series of Co/TiO2 catalysts were prepared by incipient wetness impregnation. The pH value of the impregnation solution was adjusted by using nitric acid and urea. The XRD, TPR and XPS characterization results indicate that the change of the pH value of the impregnation solution is correlated with the crystal particle size of cobalt oxide species （Co3O）, dispersion behavior and metal-support interaction. When the pH value of the solution is higher than the IEP （ion equipotential point） of titania, the larger Co3O4 particle size could be obtained on the surface of the catalyst. High pH value favores the adsorption and dispersion of active cobalt species over the titanium dioxide, and facilitates the interaction between cobalt and titania, and depresses the reduction degree of the catalyst. In the F-T reaction, catalysts prepared at high pH value have low activities and high methane selectivities. When the pH value of the solution is lower than the IEP of titania, the Co3O4 particle size is small, the interactions between cobalt species and support are weak and the reduction degrees are high, which further enhance the F-T reaction activity and suppress methane selectivity.展开更多
利用H2O2做氧化剂9,含Co为2.5%的Co/TiO2做催化剂,用催化氧化的方法降解茜素红模拟废水。考察了茜素红初始浓度、H2O2用量、催化剂用量、pH值和温度等体系相关的动力学因素。结果表明:利用Co/TiO2催化H2O2分解产生的游离羟基能够有效破...利用H2O2做氧化剂9,含Co为2.5%的Co/TiO2做催化剂,用催化氧化的方法降解茜素红模拟废水。考察了茜素红初始浓度、H2O2用量、催化剂用量、pH值和温度等体系相关的动力学因素。结果表明:利用Co/TiO2催化H2O2分解产生的游离羟基能够有效破坏茜素红有机大分子结构,催化降解90 m in后茜素红降解率能达到90%;其COD去除率可达70%。展开更多
文摘A series of Co/TiO2 catalysts were prepared by incipient wetness impregnation. The pH value of the impregnation solution was adjusted by using nitric acid and urea. The XRD, TPR and XPS characterization results indicate that the change of the pH value of the impregnation solution is correlated with the crystal particle size of cobalt oxide species （Co3O）, dispersion behavior and metal-support interaction. When the pH value of the solution is higher than the IEP （ion equipotential point） of titania, the larger Co3O4 particle size could be obtained on the surface of the catalyst. High pH value favores the adsorption and dispersion of active cobalt species over the titanium dioxide, and facilitates the interaction between cobalt and titania, and depresses the reduction degree of the catalyst. In the F-T reaction, catalysts prepared at high pH value have low activities and high methane selectivities. When the pH value of the solution is lower than the IEP of titania, the Co3O4 particle size is small, the interactions between cobalt species and support are weak and the reduction degrees are high, which further enhance the F-T reaction activity and suppress methane selectivity.
文摘利用H2O2做氧化剂9,含Co为2.5%的Co/TiO2做催化剂,用催化氧化的方法降解茜素红模拟废水。考察了茜素红初始浓度、H2O2用量、催化剂用量、pH值和温度等体系相关的动力学因素。结果表明:利用Co/TiO2催化H2O2分解产生的游离羟基能够有效破坏茜素红有机大分子结构,催化降解90 m in后茜素红降解率能达到90%;其COD去除率可达70%。
