• 文献标题:   Onion-Like Graphene Carbon Nanospheres as Stable Catalysts for Carbon Monoxide and Methane Chlorination
  • 文献类型:   Article
  • 作  者:   CENTI G, BARBERA K, PERATHONER S, GUPTA NK, EMBER EE, LERCHER JA
  • 作者关键词:   carbon, chlorination, graphene, nanostructure, strained molecule
  • 出版物名称:   CHEMCATCHEM
  • ISSN:   1867-3880 EI 1867-3899
  • 通讯作者地址:   Univ Messina
  • 被引频次:   7
  • DOI:   10.1002/cctc.201500662
  • 出版年:   2015

▎ 摘  要

Thermal treatment induces a modification in the nanostructure of carbon nanospheres that generates ordered hemi-fullerene-type graphene shells arranged in a concentric onion-type structure. The catalytic reactivity of these structures is studied in comparison with that of the parent carbon material. The change in the surface reactivity induced by the transformation of the nanostructure, characterized by TEM, XRD, X-ray photoelectron spectroscopy (XPS), Raman, and porosity measurements, is investigated by multipulses of Cl-2 in inert gas or in the presence of CH4 or CO. The strained CC bonds (sp(2)-type) in the hemi-fullerene-type graphene shells induce unusually strong, but reversible, chemisorption of Cl-2 in molecular form. The active species in CH4 and CO chlorination is probably in the radical-like form. Highly strained CC bonds in the parent carbon materials react irreversibly with Cl-2, inhibiting further reaction with CO. In addition, the higher presence of sp(3)-type defect sites promotes the formation of HCl with deactivation of the reactive CC sites. The nano-ordering of the hemi-fullerene-type graphene thus reduces the presence of defects and transforms strained CC bonds, resulting in irreversible chemisorption of Cl-2 to catalytic sites able to perform selective chlorination.