Synthesis And Catalytic Properties Of Carbon Nanotube Supported Metal Catalysts

Carbon nanotube (CNT) is a novel carbon material with unique structure and properties, and has drawn much attention as a potential catalytic material from a viewpoint of both fundamental research and industrial uses. It has been demonstrated that the use of CNT as catalyst support can improve activity and selectivity in hydrogenation, hydroformylation and electrocatalysis. In this thesis, the effects of the preparation parameters on CNT supported metal catalysts and their catalytic performance were investigated, on the basis of which the synthesis mechanism of CNT supported metal catalysts are addressed.The nature and structure, which are significantly influenced by the or/and treatment procedure, are crucial to the performances of catalysts. In this dissertation, CNT supported metal catalysts were prepared using three techniques including impregnation method (IP), metal organic chemical vapor deposition method (MOCVD) and a modified ethylene glycol method (EG). The effects of several preparation variables on the performance of catalysts were studied. The Co/CNT catalyst prepared by MOCVD method has a high and homogeneous dispersion of spherical Co metal particles with a narrow size distribution. The amounts of oxygen-containing functional groups and metal loading on CNT are found to be the key factors in controlling the metal particle size and distribution of the metal particles deposited on the CNT. For the hydroformylation of 1 -octene, the Co/CNT catalyst prepared by MOCVD is superior to those prepared by other methods, and shows significantly higher activity and regioselectivity. The excellent catalytic performance of Co/CNT prepared by MOCVD can be attributed to homogeneous distribution and small size of cobalt metal particles.A facile ethylene glycol reduction method has been developed, with which a number of metals including Pt group metals, iron group metals, Au and Ag have been successfully supported onto CNT that feature small particle size and narrow size distributions. The correlation between the activity of each metal catalyst for the decomposition of carboxylic acid and the standard formation enthalpy of each corresponding metal's carboxylates has been found to be the guiding plot for obtaining highly dispersed metallic nanoparticles on CNT supports. This strategy can be realized by the decomposition of formic acids catalyzed by various metals, a reaction that is usually used to illustrate connections...