Abstract
Prohibiting deep oxidation remains a challenging task in oxidative dehydrogenation of light alkane since the targeted alkene is more reactive than parent substrate. Here we tailor dual active sites to isolate dehydrogenation and oxidation instead of homogeneously active sites responsible for these two steps leading to consecutive oxidation of alkene. The introduction of HY zeolite with acid sites, three-dimensional pore structure and supercages gives rise to Ni2+ Lewis acid sites (LAS) and NiO nanoclusters confined in framework wherein catalytic dehydrogenation of ethane occurs on Ni2+ LAS resulting in the formation of ethene and hydrogen while NiO nanoclusters with decreased oxygen reactivity are responsible for selective oxidation of hydrogen rather than over-oxidizing ethene. Such tailored strategy achieves near 100% ethene selectivity and constitutes a promising basis for highly selective oxidation catalysis beyond oxidative dehydrogenation of light alkane.
Highlights
Prohibiting deep oxidation remains a challenging task in oxidative dehydrogenation of light alkane since the targeted alkene is more reactive than parent substrate
High-angle annular dark-filed scanning transmission electron microscopy (HAADF-STEM) combined with energy dispersive spectrometer (EDS) mappings showed that Ni species with the exclusive valence state of +2 proved by Ni k-edge X-ray absorption near-edge spectrum (XANES) (Supplementary Fig. 2) were highly dispersed and well distributed with Si, Al and O elements with particle size ranging from 0.6 to 1.7 nm in xNi/HY, which indicated that they entered the framework of HY for xNi/ HY (Supplementary Figs. 1, 3a−c)
It was reported that the introduction of metal species into zeolites would induce the generation of Lewis acid sites (LAS) by the substitution of Brønsted acid sites (BAS)[43]
Summary
Prohibiting deep oxidation remains a challenging task in oxidative dehydrogenation of light alkane since the targeted alkene is more reactive than parent substrate. The oxidative dehydrogenation of light alkanes to olefins (ODH) which are important building blocks for a handful of industrial processes is a well-known example of such a challenging reaction that is a promising alternative to the current industrial practice of steam cracking with no thermodynamic limitation, coke formation, and large CO2 emission but difficult to realize commercialized utilization impeded by the liable deep oxidation[6,7,8,9] This was because alkene is facile to be further oxidized before its desorption or re-adsorbed on the active sites of dehydrogenation (usually oxygen species) according to the Mars–van Krevelen mechanism[1,10,11] which resulted from its higher affinity and reactivity than alkane to most surfaces for those of V- and Ni-based catalysts which have been studied most for ODH12–17. It can be feasible to avert over-oxidation that dehydrogenation and oxidation occur on different active sites
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
