A DFT study of boron nitride-confined nickel single atoms for the oxidation of methane to methanol

Abstract

Direct oxidation of methane to methanol (DMTM) remains an economically tantalizing but fundamentally challenging goal because of the highly stable C–H bonds. By using density functional theory calculations, we investigated the catalytic properties of single transition metals (Fe, Pd, Ni) supported on O-doped BN in different coordination environments for DMTM. The results indicated that embedding Ni into O-doped BN via two N atoms and one O atom coordination (Ni₁/O₁N₂-BN) was an efficient option for DMTM. Ni₁/O₁N₂-BN was capable of effectively activating the strong C–H bonds of CH₄ by generating key Ni–O intermediates. Besides, Ni₁/O₁N₂-BN also exhibited high selectivity for CH₃OH owing to the inhibition of CH₂ competitive species and low desorption energy of CH₃OH. Furthermore, the excellent thermal stability of Ni₁/O₁N₂-BN was verified via ab initio molecular dynamics calculations at 500 K for 10 ps. This work provides a new insight into the fundamental understanding and materials design of high-efficiency catalysts for DMTM.