Metathesis of 1-butene and 2-butene to propene over Re_2O_7 supported on macro-mesoporous γ-alumina prepared via a dual template method

Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.

Fabrication of La1-xCaxFeO3 perovskite-type oxides with macro-mesoporous structure via a dual-template method for highly efficient soot combustion

A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.

Template-free synthesis of hierarchically macro-mesoporous Mn-TiO2 catalysts for selective reduction of NO with NH3

This study described a template-flee method for the synthesis of hierarchically macro-mesoporous Mn- TiO2 catalysts. The promoting effect of Mn doping and the hierarchically macro-mesoporous architecture on TiO2 based catalysts was also investigated for the selective reduction of NO with NH3. The results show that the catalytic performance of TiO2 based catalysts was improved greatly after Mn doping. Meanwhile, the Mn- TiO2 catalyst with the hierarchically macro-mesoporous architecture has a better catalytic activity than that without such an architecture.