Design Of Functional Catalysts And Their Application In The Catalytic Reaction Of Carbon Dioxide

Recently, the researches about the CO₂ as reactant have attracted more and more attentions all over the world. Among the reactions, the hydrogenation of CO₂ to prepare formic acid and its derivative, which promoted by ruthenium phosphine complexes, becomes to be a hot area. A series of amine modified phosphine ligands had been synthesized by the reaction of [Ph2P(CH2OH)2]+Cl- with ethylenediamine, piperazine, dibutylamine, morpholine and dimethylamine. The quaternary phosphoniums were formed by the reaction of those phosphine ligands with fluoride boric acid, hydrochloric acid and acetic acid, and characterized by NMR technology. The catalyst forming in situ from the reaction of quaternary phosphonium with RuCl3 and amine in following reaction was used to catalyze the hydrogenation of carbon dioxide in presence of morphine. The effects of reaction conditions on the activity have been explored. The results indicate that the catalytic activity can be increased by introduction of amine group into phosphine molecular to form modified phosphine ligands. In this catalytic system, the phosphine released in situ from the reaction of phosphonium with amine reacted further with RuCl3 to form the"catalytic center".Several ruthenium-phosphine complexes had been synthesized by the reaction of RuCl3 with phosphine ligands. Their catalytic activity in the hydrogenation of CO₂ in the presence of morpholine was investigated. Compared to the catalyst forming in situ, the catalytic activity of those complexes reduced a little RuCl3/DPPE has been used as catalyst to promote the hydrogenation of carbon dioxide in presence of dibutylamine. The effects of reaction conditions such as temperature, the pressure of CO₂ and H2 on the hydrogenation of CO₂ had been explored. The reaction mechanism has been proposed primary.In addition, several nitrogen contained ligands were synthesized by the addition reaction of methyl acrylate with alkyl amines. The activity of the catalytic system, which is formed by amine and RuCl3, was investigated in the model reaction of the hydrogenation of CO₂ in the presence of morpholine. The catalytic activity of this system is pretty low. The carbonylation of CO₂ with cyclopentadiene had also been tested primarily using the catalytic system of NiCl2 and cyclopentadiene. And the conversion is also very low.