A series of Zn-modified Hβ (Zn/Hβ) catalysts were prepared by using the different zinc precursors such as ZnSO4·7H2O, ZnCl2, C4H6O4Zn·2H2O and Zn(NO3)2·6H2O, and their catalytic performance in the ethanol conversion to propylene reaction was evaluated. Results indicate the amount and strength distribution of acid sites of the Zn/Hβ catalysts were easily tuned by employing different type of zinc precursors. More importantly, when the Zn species were introduced to the Hβ, the propylene yield was significantly enhanced, whereas the yields of the byproducts such as ethylene and C2-C4 alkanes were remarkably suppressed. For the catalyst prepared by using the ZnCl2 precursor (Zn/Hβ-C), a higher propylene yield up to 43.4% was achieved as a result of the moderate amount and distribution of acid sites. The average coking rate of the used Zn/Hβ catalysts strongly depended on the amount of total acid sites, especially the strong acid sites, i.e., the higher the amount of total acid sites of the catalyst, the greater the average coking rate. For the catalyst prepared by using the ZnSO4·7H2O precursor, Zn/Hβ-S exhibited a better stability even after depositing more coke, which is due to the higher amount of strong acid sites.

In this study, we analyzed the optical observations of a subluminous Type Ia supernova (SN Ia) 2017fzw, which exhibited high photospheric velocity (HV) at B-band maximum light. The absolute B-band peak magnitude was determined to be M^B_max = -17.77  0.10 mag, similar to 91bg-like SNe Ia. The decline rate of the B-band light curve was estimated to be Dm15(B) = 1.60  0.06 mag. The spectra of SN 2017fzw were similar to those of 91bg-like SNe Ia, with prominent Ti II and Si II l5972 features at early phases, gradually transitioning to spectra resembling normal (mainly HV subclass) SNe Ia at later phases, with a stronger Ca II NIR feature. Notably, SN 2017fzw exhibited spectral evolution features similar to those of HV SNe Ia at all phases, with a maximum-light Si II l6355 velocity of 13, 786  414 km s