Institution: | 1. Ocean College, Minjiang University, 350108 Fuzhou, China;2. Ocean College, Minjiang University, 350108 Fuzhou, China
Fujian Engineering and Research Centre of New Chinese Lacquer Material, Ocean College, Minjiang University, 350108 Fuzhou, China
Fujian Provincial University Engineering Research Centre of Green Materials and Chemical Engineering, Ocean College, Minjiang University, 350108 Fuzhou, China;3. Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria, 3122 Australia |
Abstract: | Three novel amphiphilic poly(ionic liquid) (PIL)/Wells–Dawson-type phosphovanadomolybdate (V-POM) ionic composites with tunable oxidative catalytic activity and unique nanostructure were synthesized using carboxylic acid-functionalized PIL and H7P2Mo17VO62], H8P2Mo16V2O62] and H9P2Mo15V3O62] as synthetic units via self-assembly in water. The results of characterization indicated that V-POM anions were finely dispersed in the PIL cation framework, and their structures were well preserved. The three composites are amorphous V-POM salts of PIL cation with a considerable thermal stability, and an open three-dimensional network structure with hierarchical porosity. The as-synthesized composites were found to be efficient heterogeneous catalysts for the direct hydroxylation of benzene to phenol with H2O2 in the liquid phase. Under optimum conditions, a phenol yield of 37.3% was achieved with selectivity of 100%. The high catalytic performance could be attributed to the synergistic catalytic effect between V-POM anion and carboxylic acid-functionalized PIL cation framework, and good benzene adsorption and phenol desorption ability of amphiphilic micropores in the structure of the composites. Additionally, these composites exhibited high stability under the reaction conditions and could be easily recovered and reused at least six times without noticeably loss of activity. |