A set of mono-and bimetallic（Zn-Co） supported ZSM-5 catalysts was first prepared by PEG-additive method. The physicochemical properties of the catalysts were investigated by FTIR, XPS, XRD, N2adsorption-desorption m...A set of mono-and bimetallic（Zn-Co） supported ZSM-5 catalysts was first prepared by PEG-additive method. The physicochemical properties of the catalysts were investigated by FTIR, XPS, XRD, N2adsorption-desorption measurements, SEM, EDS and NH3-TPD techniques. The physicochemical properties showed that the Zn Co2O4 spinel oxide was formed on the ZSM-5 support and provided effectual synergetic effect between Zn and Co species for the bimetallic catalyst. Furthermore, bimetallic supported ZSM-5 catalyst exhibited weak, moderate and strong acidic sites, while the monometallic supported ZSM-5 catalyst showed only weak and moderate or strong acidic sites. Their catalytic performances for thermal decomposition of hexamethylene–1,6–dicarbamate（HDC） to hexamethylene–1,6–diisocyanate（HDI） were then studied. It was found that the bimetallic supported ZSM-5 catalysts,especially Zn-2Co/ZSM-5 catalyst showed excellent catalytic performance due to the good synergetic effect between Co and Zn species, which provided a suitable contribution of acidic sites. HDC conversion of 100% with HDI selectivity of 91.2% and by-products selectivity of 1.3% could be achieved within short reaction time of 2.5 h over Zn-2Co/ZSM-5 catalyst.展开更多
基金supported by National Natural Science Foundation of China(Nos.21476244 and 21406245)Youth Innovation Promotion Association CAS
文摘A set of mono-and bimetallic（Zn-Co） supported ZSM-5 catalysts was first prepared by PEG-additive method. The physicochemical properties of the catalysts were investigated by FTIR, XPS, XRD, N2adsorption-desorption measurements, SEM, EDS and NH3-TPD techniques. The physicochemical properties showed that the Zn Co2O4 spinel oxide was formed on the ZSM-5 support and provided effectual synergetic effect between Zn and Co species for the bimetallic catalyst. Furthermore, bimetallic supported ZSM-5 catalyst exhibited weak, moderate and strong acidic sites, while the monometallic supported ZSM-5 catalyst showed only weak and moderate or strong acidic sites. Their catalytic performances for thermal decomposition of hexamethylene–1,6–dicarbamate（HDC） to hexamethylene–1,6–diisocyanate（HDI） were then studied. It was found that the bimetallic supported ZSM-5 catalysts,especially Zn-2Co/ZSM-5 catalyst showed excellent catalytic performance due to the good synergetic effect between Co and Zn species, which provided a suitable contribution of acidic sites. HDC conversion of 100% with HDI selectivity of 91.2% and by-products selectivity of 1.3% could be achieved within short reaction time of 2.5 h over Zn-2Co/ZSM-5 catalyst.
