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

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 (Ni 1 /O 1 N 2 -BN) was an efficient option for DMTM. Ni 1 /O 1 N 2 -BN was capable of effectively activating the strong C-H bonds of CH 4 by generating key Ni-O intermediates. Besides, Ni 1 /O 1 N 2 -BN also exhibited high selectivity for CH 3 OH owing to the inhibition of CH 2 competitive species and low desorption energy of CH 3 OH. Furthermore, the excellent thermal stability of Ni 1 /O 1 N 2 -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.