Preparation Of The Catalysts For Knoevenagel Condensation Reaction And Their Catalytic Performance

Knoevenagel condensation reaction is one of the classic reactions to synthesize C=C chemicals. Many catalysts have been fabricated for this kind of reaction. In this thesis, nitrogen-doped carbon-based materials and ceria-zirconia solid solution were prepared via simple methods. In the carbon-based materials, CMK-3and carbon spheres from hydrothermal treating of glucose were treated with NH3or ammonia solution to get N-doped carbon materials. For preparing ceria-zirconia solid solutions, calcination or hydrothermal treating was adopted. The prepared catalysts were characterized by XRD, N2adsorption-desorption, TEM, XPS and so on, and the catalytic performance were tested in Knoevenagel condensation.Nitrogen-doped carbon-based materials N/CMK-3(1) and N/CMK-3(2) were prepared by treaing CMK-3with NH3or ammonia solution, respectively. It is revealed that CMK-3still maintained ordered mosostructures after different treating processes. The dopping amounts of N/CMK-3(1) and N/CMK-3(2) is0.52mol%and0.73mol%, respectively. The catalytic results between N/CMK-3(1) and N/CMK-3(2) are similar. The conversion of benzaldehyde reaches91%in50minutes with the catalyst of N/CMK-3(2). Both catalysts showed good reusability for Knoevenagai reactions.Carbon spheres, which were prepared by hydrothermally treating glucose, were treated with ammonia solution or NH3to obtain N/C-1or N/C-2, with dopping amounts of2.49mol%and4.55mol%, respectively. It is found that the conversion of benzaldehyde and malonicnitrile or benzaldehyde and ethyl cyanoacetate could reach98%in50minutes or50%in75minutes, respectively, on N/C-1. Besides, the catalysts were demonstrated to be high stable. After4cycles, the catalysts present highly catalytic activity and selectivity.The ceria-zirconia solid solutions were successfully prepared via calcination or hydrothermal synthesis routes. The characterized results showed that the grain size of ceria-zirconia solid solutions is in the range of7-10nm. The catalytic results were verified dependent on the ratio of Ce to Zr or the preparing methods. Higher catalytic performance was obtained on the catalysts from hydrothermal treating. The catalyst is stable even after4runs.