Release Time:2025-06-03  Hits:

Indexed by: Journal Article

Date of Publication: 2021-01-31

Journal: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

Volume: 140

Issue: 49

Page Number: 16936-16940

ISSN: 0002-7863

Key Words: Aberrations; Atoms; Benzene; Carbon nitride; Catalyst activity; Catalytic oxidation; Copper compounds; Extended X ray absorption fine structure spectroscopy; Fabrication; Phenols; Spheres; X ray absorption, Benzene to phenol; Catalytic performance; Cyanuric acids; Hollow structure; Micro/nanostructures; Selective oxidation; Spherical aberration correction; Thermal polymerizations, Nitrogen compounds, benzene; phenol, Article; covalent bond; electron microscopy; oxidation; polymerization; reaction analysis; scanning electron microscopy; structure analysis; transmission electron microscopy; X ray diffraction

Abstract: Developing single-atom catalysts with porous micro-/nanostructures for high active-site accessibility is of great significance but still remains a challenge. Herein, we for the first time report a novel template-free preassembly strategy to fabricate porous hollow graphitic carbonitride spheres with single Cu atoms mounted via thermal polymerization of supramolecular preassemblies composed of a melamine Cu complex and cyanuric acid. Atomically dispersed Cu-N-3 moieties were unambiguously confirmed by spherical aberration correction electron microscopy and extended X-ray absorption fine structure spectroscopy. More importantly, this material exhibits outstanding catalytic performance for selective oxidation of benzene to phenol at room temperature, especially showing phenol selectivity (90.6 vs 64.2%) and stability much higher than those of the supported Cu nanoparticles alone, originating from the isolated unique Cu-N-3 sites in the porous hollow structure. An 86% conversion of benzene, with an unexpectedly high phenol selectivity of 96.7% at 60 degrees C for 12 h, has been achieved, suggesting a great potential for practical applications. This work paves a new way to fabricate a variety of single-atom catalysts with diverse graphitic carbonitride architectures.