“…Transition metal oxides with variable oxidation states have been mostly studied due to their excellent ability to adsorb and activate alkanes. − Unfortunately, their reduced counterparts with closely spaced and partially occupied d-orbitals strongly interact with reactive functional groups contained in olefins, leading to difficulty in their desorption and thus over-oxidation. ,, To this end, extensive studies have been devoted to manipulating their reactivity to olefins by creating functionalities exemplified by Mo–V–Te–Nb catalysts with a selective M1 phase, − increasing the metal–oxygen bond strength such as in doped V-based catalysts, decreasing the number of surface-active but nonselective electrophilic oxygen species such as in doped and supported Ni-based catalysts, − preventing the exposure of coordination unsaturated cations by a selective surface shell typically represented by metal oxide-supported alkali metal oxides or chlorides, ,, and tailoring dual active sites to isolate dehydrogenation and oxidization . While the selectivity to olefins was greatly enhanced by manipulating the activity of transition metal oxides from strength to weakness, the conversion decreased concurrently as a result of suppressed adsorption and activation of alkanes, thereby limiting the yield of olefins.…”