Probing the intrinsic catalytic activity of carbon nanotubes for the metal-free oxidation of aromatic thiophene compounds in ionic liquids  

作　　者：Qingqing Gu Yuxiao Ding Zigeng Liu Yangming Lin Robert Schlogl Saskia Heumann Dangsheng Su 

机构地区：[1]Shenyang National Laboratory for Material Science,Institute of Metal Research,Chinese Academy of Sciences,Wenhua Road 72,Shenyang 110016,Liaoning,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Max Planck Institute for Chemical Energy Conversion,Stiftstrasse 34-36,45470 Millheim a.d.Ruhr,Germany [4]Fritz Haber Institute of the Max Planck Society,Faradayweg 4-6,14195 Berlin,Germany

出　　处：《Journal of Energy Chemistry》2019年第5期131-137,共7页能源化学（英文版）

基　　金：provided by the National Natural Science Foundation of China(No.21503241,21133010,21261160487,51221264,21411130120,21473223,91545119,91545110);the“Strategic Priority Research Program” of the Chinese Academy of Sciences(CAS)(No.XDA09030103);CAS/State Administration for Foreign Experts Affairs(SAFEA)International Partnership Program for Creative Research Teams and the Doctoral Starting up Foundation of Liaoning Province,China(No.20121068);the financial support from Max Planck Society and China Scholarship Council

摘　　要：A metal-free catalytic system combining oxidized carbon nanotubes (oCNTs) and ionic liquids (ILs) is presented for the oxidation of aromatic thiophene compounds with H2O2 as an oxidant. The oCNTs exhibit impressively high activity and stability in the system, which show an even better performance than those of some reported metal catalysts. The ILs are proved to have indispensable influence on the enhanced catalytic performance of the oCNTs. Detailed characterization by TG-MS and XPS demonstrates that the carbonyl groups are the active sites for the oxidation process, which is further supported by the deactivation and the model catalysts experiments. The quantitative analysis of different oxygen groups in oCNTs could be achieved by an isothermal temperature programmed TG-MS method. The concentration of carbonyl groups is 1.46 mmol per 1 g oCNTs and the tuiriover frequency of oCNTs could also be obtained (10.7 h^-1 in the presence of OmimPF6). H2O2 decomposition experiments combined with the EPR results reveal that the presence of OmimPF6 can avoid the intermediate HO· to form O2 and then improve the catalytic performance of oCNTs for the oxidation of dibenzothiophene.A metal-free catalytic system combining oxidized carbon nanotubes（oCNTs） and ionic liquids（ILs） is presented for the oxidation of aromatic thiophene compounds with H2O2 as an oxidant. The oCNTs exhibit impressively high activity and stability in the system, which show an even better performance than those of some reported metal catalysts. The ILs are proved to have indispensable influence on the enhanced catalytic performance of the oCNTs. Detailed characterization by TG-MS and XPS demonstrates that the carbonyl groups are the active sites for the oxidation process, which is further supported by the deactivation and the model catalysts experiments. The quantitative analysis of different oxygen groups in oCNTs could be achieved by an isothermal temperature programmed TG-MS method. The concentration of carbonyl groups is 1.46 mmol per 1 g oCNTs and the turnover frequency of oCNTs could also be obtained（10.7 h-1 in the presence of OmimPF6）. H2O2 decomposition experiments combined with the EPR results reveal that the presence of OmimPF6 can avoid the intermediate HO· to form O2 and then improve the catalytic performance of oCNTs for the oxidation of dibenzothiophene.

关 键 词：Carbon nanotubes METAL-FREE catalysis Oxidative DESULFURIZATION Ionic liquids 

分 类 号：O4[理学—物理]