Zhang Ting, Zhang Di, Han Xinghua, Dong Ting, Guo Xinwen, Song Chunshan, Si Rui, Liu Wei, Liu Yuefeng, Zhao Zhongkui
State Key Laboratory of Fine Chemicals, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering , Dalian University of Technology , Dalian 116024 , P. R. China.
School of Chemical Engineering and Technology , North University of China , Taiyuan 030051 , P. R. China.
J Am Chem Soc. 2018 Dec 12;140(49):16936-16940. doi: 10.1021/jacs.8b10703. Epub 2018 Dec 3.
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 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 sites in the porous hollow structure. An 86% conversion of benzene, with an unexpectedly high phenol selectivity of 96.7% at 60 °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.
开发具有多孔微/纳米结构以实现高活性位点可及性的单原子催化剂具有重要意义，但仍然是一项挑战。在此，我们首次报道了一种新颖的无模板预组装策略，通过由三聚氰胺 - 铜配合物和氰尿酸组成的超分子预组装体的热聚合来制备负载单铜原子的多孔空心石墨相氮化碳球。通过球差校正电子显微镜和扩展X射线吸收精细结构光谱明确证实了原子分散的Cu-N部分。更重要的是，这种材料在室温下对苯选择性氧化为苯酚表现出优异的催化性能，特别是苯酚选择性（90.6对64.2%）和稳定性远高于单独的负载型铜纳米颗粒，这源于多孔空心结构中孤立的独特Cu-N位点。在60°C下12小时内实现了86%的苯转化率，苯酚选择性意外地高达96.7%，表明其具有巨大的实际应用潜力。这项工作为制备具有多种石墨相氮化碳结构的各种单原子催化剂铺平了一条新途径。
