Highly dispersed α-Fe_2O_3/NaY,NiO/NaY,and CuO/NaY catalyst systems were pre- pared by impregnation method.Dispersion thresholds of the transition metal oxides on NaY' zeolite were determined by XRD phase analysi...Highly dispersed α-Fe_2O_3/NaY,NiO/NaY,and CuO/NaY catalyst systems were pre- pared by impregnation method.Dispersion thresholds of the transition metal oxides on NaY' zeolite were determined by XRD phase analysis.The dispersion capacities of the transition metal oxides on NaY zeolite are much lower than that estimated on the basis of a closed packed monolayer in the micro pores.The catalytic activity and selectivity of the highly dispersed oxide catalyst systems for ethylben- zene and cyclohexane dehydrogenation reactions were reported.展开更多
In this paper,the as-cast Mg85Cu5Ni10 alloy and Mg85Cu5Ni10-x wt%CeO2(x=0,4,8)alloys were prepared successfully by vacuum induction smelting and ball milling.The microstructure,hydrogen absorption/desorption kinetics ...In this paper,the as-cast Mg85Cu5Ni10 alloy and Mg85Cu5Ni10-x wt%CeO2(x=0,4,8)alloys were prepared successfully by vacuum induction smelting and ball milling.The microstructure,hydrogen absorption/desorption kinetics and thermodynamics performances of the alloys were studied in detail.The results show that the Mg85Cu5Ni10 alloys with CeO2 additive have faster hydrogenation/dehydrogenation kinetics and better thermodynamic properties.The dehydrogenation activation energy is reduced to 81.211 kJ/mol from 119.142 by adding 8 wt%CeO2.CeO2 contributes to producing structural defects,nanocrystallines,grain boundaries,partial amorphous,lattice dislocations and cracks which are favorable to provide more hydrogen diffusion channels during hydriding/dehydriding process.Meanwhile,CeO2 additive weakens the bond energy of Mg-H.These micro structural changes caused by CeO2 additive improve the hydrogen storage performance of Mg85Cu5Ni10 markedly.展开更多
基金the National Natural Science Foundation of China
文摘Highly dispersed α-Fe_2O_3/NaY,NiO/NaY,and CuO/NaY catalyst systems were pre- pared by impregnation method.Dispersion thresholds of the transition metal oxides on NaY' zeolite were determined by XRD phase analysis.The dispersion capacities of the transition metal oxides on NaY zeolite are much lower than that estimated on the basis of a closed packed monolayer in the micro pores.The catalytic activity and selectivity of the highly dispersed oxide catalyst systems for ethylben- zene and cyclohexane dehydrogenation reactions were reported.
基金Project supported by the National Natural Science Foundation of China(51761032,51901105,51871125)。
文摘In this paper,the as-cast Mg85Cu5Ni10 alloy and Mg85Cu5Ni10-x wt%CeO2(x=0,4,8)alloys were prepared successfully by vacuum induction smelting and ball milling.The microstructure,hydrogen absorption/desorption kinetics and thermodynamics performances of the alloys were studied in detail.The results show that the Mg85Cu5Ni10 alloys with CeO2 additive have faster hydrogenation/dehydrogenation kinetics and better thermodynamic properties.The dehydrogenation activation energy is reduced to 81.211 kJ/mol from 119.142 by adding 8 wt%CeO2.CeO2 contributes to producing structural defects,nanocrystallines,grain boundaries,partial amorphous,lattice dislocations and cracks which are favorable to provide more hydrogen diffusion channels during hydriding/dehydriding process.Meanwhile,CeO2 additive weakens the bond energy of Mg-H.These micro structural changes caused by CeO2 additive improve the hydrogen storage performance of Mg85Cu5Ni10 markedly.
