2024 AIChE Annual Meeting

Stability of Doped NiO Catalysts for Ethane Oxidative Dehydrogenation

Ethylene is a critical chemical building block in the petrochemical industry, while global ethylene
consumption is expected to grow 6.1% every year to more than 200 million metric tons in 2020.
However, the conventional industrial production method, steam cracking, is highly energy-
intensive and leads to severe coke formation. Meanwhile, NiO-based materials have emerged as
promising catalysts for an environmentally friendly alternative through ethane oxidative
dehydrogenation (EODH), and the catalytic performance can be significantly improved by doping
NiO with various elements (M-NiO).

To understand the nanoscale effects of dopant on the stability of M-NiO during EODH, the highly
active (110) facet is investigated using density functional theory and ab initio phase diagrams. A
systematic screening is conducted, examining simultaneous factors of dopant element (Al, Mo, Nb,
Sn, Ti, V, W, Zr), dopant placement (surface or subsurface), oxygen vacancies (surface or
subsurface), and surface oxygen species (O* or O2*) adsorption. The result reveals the dominant
(most stable) structures for various M-NiO(110) systems under environmental conditions varying
oxygen presence and temperature. Overall, this approach not only identifies the dominant
structures during the EODH process but also provides a framework to accelerate experimental
screening of M-NiO catalysts during working conditions.