In this paper, CaxZn10-xFe20 catalysts were prepared by the co-precipitation method and applied to CO 2 hydrogenation. The experimental results show that the CO 2 conversion of the catalyst Ca1Zn9Fe20 at a Ca doping amount of 1 mmol can reach 57.91 %, which is 13.5 % more than the CO 2 conversion of the catalyst Zn10Fe20. Moreover, the catalyst Ca1Zn9Fe20 has the lowest selectivity for both CO and CH 4, with 7.40 % and 6.99 %, respectively. The catalysts were characterized by XRD, N 2 adsorption-desorption, CO 2 -TPD, H 2 -TPR, and XPS. The results demonstrate that the doping of Ca increases the basic sites on the catalyst surface and thus allows the catalyst to adsorb more CO 2 to promote the reaction. Besides, the Ca doping amount of 1 mmol can suppress the formation of graphitic carbon on the catalyst surface and prevent the excess graphitic carbon from covering the active site Fe 5 C 2 .
A series of M@MIL‐101(Cr) (M=Cu, Co, Ni and Mn) adopting impregnation method were fabricated as heterogeneous catalysts to oxidize styrene to benzaldehyde with tert‐butyl hydroperoxide (TBHP). The morphology of the MIL‐101(Cr) was nicely retained after the uniform dispersion of metals. In order to obtain the optimized reaction conditions, various in‐depth investigations were carried out to evaluate the effects of reaction time and reaction temperature on catalytic efficiency. Importantly, the Cu@MIL‐101(Cr) performed best in this study, the highest styrene conversion and the benzaldehyde selectivity can reach 97.45 % and 84.39 %, respectively, which revealed the synergetic effects of Cu2+ and Cr3+ in Cu@MIL‐101(Cr) on the styrene oxidation. Furthermore, the result of a three‐cycle experiment demonstrated the good recyclability of Cu@MIL‐101(Cr) without considerable structural deterioration and loss in activation. A possible mechanism of oxidation of styrene by using Cu@MIL‐101(Cr) and TBHP was also proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.