In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal di...In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal distribution. The distribution parameters were obtained by kinetic data fitting, which depends on the chemical and geometric characteristics of both the iron oxide and the promoter.展开更多
The reduction behavior of CuO supported on ZrO2 and Al2O3 has been investigated by temperature-programmed reduction (TPR) and TG techniques. The oaldation activity of CO on the catalysts has also been studied. It has ...The reduction behavior of CuO supported on ZrO2 and Al2O3 has been investigated by temperature-programmed reduction (TPR) and TG techniques. The oaldation activity of CO on the catalysts has also been studied. It has been found that there is obvious difference between TPR profiles of ZrO2 supported CuO and Al2O3 supported catalysts, the monolayer CuO on ZrO2 is easily reduced, and which leads to a dramatic increase in oxidation activity.展开更多
Pt Sn/MgAl 2O 4 catalysts prepared by co impregnation with nominal 0 35% platinum and varying content of tin (0～2 5%) were characterized by temperature programmed reduction (TPR) and temperature programmed desorption...Pt Sn/MgAl 2O 4 catalysts prepared by co impregnation with nominal 0 35% platinum and varying content of tin (0～2 5%) were characterized by temperature programmed reduction (TPR) and temperature programmed desorption of hydrogen (H 2 TPD). TPR results showed that platinum catalyzed the reduction of tin. However, the average oxidation state of tin after reduction depended upon the concentration of tin on the catalysts. H 2 TPD data indicated that tin addition inhibited the inactivated adsorption of hydrogen but promoted the activated adsorption, implying that tin modified both the ensembles of platinum and metal support interface, thus increasing hydrogen mobility and promoting hydrogen spillover.展开更多
采用H2-TPR技术研究了不同方法制备的Mo/HZSM-5催化剂,并借助1H MAS NMR等表征手段对Mo/HZSM-5催化剂还原过程中可能出现的6个TPR谱峰进行了详细归属,首次指认了分布于分子筛孔道内并与B酸性位相互作用的Mo物种的还原峰.此外,还考察了各...采用H2-TPR技术研究了不同方法制备的Mo/HZSM-5催化剂,并借助1H MAS NMR等表征手段对Mo/HZSM-5催化剂还原过程中可能出现的6个TPR谱峰进行了详细归属,首次指认了分布于分子筛孔道内并与B酸性位相互作用的Mo物种的还原峰.此外,还考察了各种Mo基催化剂在甲烷无氧芳构化反应中的催化性能.结果表明,与B酸中心相互作用的Mo物种比其他形式的Mo物种具有更好的活性和稳定性.展开更多
Core-shell nanoparticles Fe@Fe3O4 supported on activated carbon (AC) and carbon nanotubes (CNTs) have been studied by H2 temperature-programmed reduction (TPR). Nanoparticles with size of 6.5 nm were synthesized by ir...Core-shell nanoparticles Fe@Fe3O4 supported on activated carbon (AC) and carbon nanotubes (CNTs) have been studied by H2 temperature-programmed reduction (TPR). Nanoparticles with size of 6.5 nm were synthesized by iron(II) oleate thermal decomposition and were supported on activated carbon and carbon nanotubes by colloid deposition method. The nanoparticles Fe@Fe3O4 are characterized by TEM and IR. Reduction of nanoparticles on AC starts at 140?C, whereas reduction of nanoparticles on CNTs starts at 200?C. Moreover, gasification of CNTs with methane releasing starts at 450?C, whereas gasification of AC is negligible at temperatures up to 800?C. All these findings illustrate a strong difference in the interaction between nanoparticles and the support material for AC and CNTs.展开更多
文摘In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal distribution. The distribution parameters were obtained by kinetic data fitting, which depends on the chemical and geometric characteristics of both the iron oxide and the promoter.
文摘The reduction behavior of CuO supported on ZrO2 and Al2O3 has been investigated by temperature-programmed reduction (TPR) and TG techniques. The oaldation activity of CO on the catalysts has also been studied. It has been found that there is obvious difference between TPR profiles of ZrO2 supported CuO and Al2O3 supported catalysts, the monolayer CuO on ZrO2 is easily reduced, and which leads to a dramatic increase in oxidation activity.
文摘Pt Sn/MgAl 2O 4 catalysts prepared by co impregnation with nominal 0 35% platinum and varying content of tin (0～2 5%) were characterized by temperature programmed reduction (TPR) and temperature programmed desorption of hydrogen (H 2 TPD). TPR results showed that platinum catalyzed the reduction of tin. However, the average oxidation state of tin after reduction depended upon the concentration of tin on the catalysts. H 2 TPD data indicated that tin addition inhibited the inactivated adsorption of hydrogen but promoted the activated adsorption, implying that tin modified both the ensembles of platinum and metal support interface, thus increasing hydrogen mobility and promoting hydrogen spillover.
文摘采用H2-TPR技术研究了不同方法制备的Mo/HZSM-5催化剂,并借助1H MAS NMR等表征手段对Mo/HZSM-5催化剂还原过程中可能出现的6个TPR谱峰进行了详细归属,首次指认了分布于分子筛孔道内并与B酸性位相互作用的Mo物种的还原峰.此外,还考察了各种Mo基催化剂在甲烷无氧芳构化反应中的催化性能.结果表明,与B酸中心相互作用的Mo物种比其他形式的Mo物种具有更好的活性和稳定性.
文摘Core-shell nanoparticles Fe@Fe3O4 supported on activated carbon (AC) and carbon nanotubes (CNTs) have been studied by H2 temperature-programmed reduction (TPR). Nanoparticles with size of 6.5 nm were synthesized by iron(II) oleate thermal decomposition and were supported on activated carbon and carbon nanotubes by colloid deposition method. The nanoparticles Fe@Fe3O4 are characterized by TEM and IR. Reduction of nanoparticles on AC starts at 140?C, whereas reduction of nanoparticles on CNTs starts at 200?C. Moreover, gasification of CNTs with methane releasing starts at 450?C, whereas gasification of AC is negligible at temperatures up to 800?C. All these findings illustrate a strong difference in the interaction between nanoparticles and the support material for AC and CNTs.
