posted on 2024-02-02, 13:04authored byYicong Chai, Yanliang Zhou, Sen Lin, Xiaodong Wang, Jian Lin
Olefins are important building blocks
that have been
extensively
used to produce diverse consumer products in petrochemical industry.
Owing to the requirement of low-carbon-footprint processes and the
increasing use of light alkanes sourced from shale gas, an environmentally
friendly and economic route alternative to the state-of-the-art steam
cracking of crude oil has been investigated for olefin production.
The oxidative dehydrogenation (ODH) of alkanes to olefins has attracted
wide attention due to the absence of thermodynamic limitations and
coke formation. However, excessive oxidation of olefin is prone to
occur in this process. Developing a suitable ODH catalyst with high
performance, particularly with enhanced selectivity, is more and more
urgent but still remains a challenge. In this Review, we talk about
the representative currently developed isolation strategies to optimize
the selectivity of olefins via the ODH process, particularly for the
conversion of ethane to ethylene, which include the dispersion regulation
of metal oxide, the isolation of metal and nonmetal sites, the construction
of dual functional sites to isolate dehydrogenation and oxidation
steps, and the adoption of selective oxygen species with the promotion
of soft oxidants as reactants. Furthermore, the mechanistic aspects
about the activation of ethane and the participation of oxygen species
for tailoring the selectivity are then classified and discussed in
detail. Finally, the perspectives and the emerging technologies for
the ODH process are listed and evaluated.