Propane nonoxidative dehydrogenation (PDH) is a promising route to produce propylene with the development of shale gas exploration technology. Co-based catalysts with low cost and low toxicity could activate C−H effectively, but they suffer from deactivation with coke formation. In this work, a catalyst formed by incorporating highly dispersed Co sites into a Silicalite-1 zeolite framework (Co-Silicalite-1) is synthesized by a hydrothermal protocol in the presence of ammonia, which exhibits superior propane dehydrogenation catalytic performance with 0.0946 mmol C 3 H 6 •s −1 • g Co −1 and propylene selectivity higher than 98.5%. It also shows outstanding catalytic stability and coking resistance in a 3560 min time-on-stream. Combined characterization results demonstrate that the tetrahedrally coordinated Co 2+ site serves as the PDH catalytic active site, which is stabilized by Si−O units of the zeolite framework. Incorporation of Co sites into the zeolite framework could avoid the reduction of Co species to metallic Co. Moreover, the catalytic performance is improved by the enhanced propane adsorption and propylene desorption.

A facile strategy is applied to construct Fe supported ZSM-5 (Fe/HZ5-HTS) via hydrothermal post-treatment and applied to ethane non-oxidative dehydrogenation. Compared with Fe/ HZ5-IWI prepared by incipient wetness impregnation, Fe/HZ5-HTS exhibits superior catalytic activity and long catalyst stability with 6000 minutes time-on-stream. An obvious volcanic curve is observed between the ethylene generation rate and Fe content, and 1.0Fe/HZ5-HTS exhibits the highest ethylene generation rate with 0.166 mmol C 2 H 4 s À 1 g Fe À 1 over different Fe loading, which is twice as much as that of 1.0Fe/HZ5-IWI. According to various characterizations, isolated Fe 3 + species and carburized Fe species are active sites, and the better catalytic performance over 1.0Fe/HZ5-HTS is ascribed to more disperse Fe species and exposing more Fe species in the surface. Besides, the lower ethylene desorption temperature and higher ethane desorption temperature over Fe/HZ5-HTS could suppress the overreaction of the ethylene to generate coke and increase ethane residence reaction time, resulting in less coke deposition and facilitating the catalytic performance.

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