Dynamic evolution of nitrogen and oxygen dual-coordinated single atomic copper catalyst during partial oxidation of benzene to phenol

• Published in: Nano research Vol. 15; no. 4; pp. 3017 - 3025
• Main Authors: Chen, Weiming, Jin, Hongqiang, He, Feng, Cui, Peixin, Cao, Changyan, Song, Weiguo
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.04.2022
• Subjects: Atomic/Molecular Structure and Spectra; Benzene; Biomedicine; Biotechnology; Catalysts; Catalytic oxidation; Chemistry and Materials Science; Condensed Matter Physics; Coordination numbers; Copper; Density functional theory; Evolution; Hydrocarbons; Hydrogen peroxide; Hydroxylation; Materials Science; Mathematical analysis; Nanotechnology; Nitrogen; Oxidation; Oxygen; Phenols; Reaction mechanisms; Research Article; Selectivity; Single atom catalysts; phenol; benzene oxidation; single atom catalyst; dynamic evolution; coordination
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-021-3936-4

Single atom catalysts (SACs) with metal 1 -N x sites have shown promising activity and selectivity in direct catalytic oxidation of benzene to phenol. The reaction pathway is considered to be involving two steps, including a H 2 O 2 molecule dissociated on the metal single site to form the (metal 1 -N x )=O active site, and followed by the dissociation of another H 2 O 2 on the other side of metal atom to form O=(metal 1 -N x )=O intermediate center, which is active for the adsorption of benzene molecule via the formation of a C-O bond to form phenol. In this manuscript, we report a Cu SAC with nitrogen and oxygen dual-coordination (Cu 1 -N 3 O 1 moiety) that doesn’t need the first H 2 O 2 activation process, as verified by both experimental and density function theory (DFT) calculations results. Compared with the counterpart nitrogen-coordinated Cu SAC (denoted as Cu 1 /NC), Cu SAC with nitrogen and oxygen dual-coordination (denoted as Cu 1 /NOC) exhibits 2.5 times higher turnover frequency (TOF) and 1.6 times higher utilization efficiency of H 2 O 2 . Particularly, the coordination number (CN) of Cu atom in Cu 1 /NOC maintains four even after H 2 O 2 treatment and reaction. Combining DFT calculations, the dynamic evolution of single atomic Cu with nitrogen and oxygen dual-coordination in hydroxylation of benzene is proposed. These findings provide an efficient route to improve the catalytic performance through regulating the coordination environments of SACs and demonstrate a new reaction mechanism in hydroxylation of benzene to phenol reaction.