Study Of The Catalytic Performance Of Composite Transition Metal Materials On The Carboxylation Of Methanol To Dimethyl Carbonate And The Synthesis Of 5-hydroxymethyl-furfural

Nowadays, the utilization of fossil fuels hasn’t only promoted the development of human society, but also caused increasingly severe atmosphere pollution. Especially green house gas, including CO₂, caused the global warming and abnormal climate. On one hand, due to the danger of the global warming, reducing the concentration of CO₂ in atmosphere becomes more and more important. On the other, because of its abundance, CO₂ is cheap enough to be a valuable and renewable carbon source. Among these CO₂ conversions, the transformation of CO₂ into organic carbonate is convenient and low-energy consuming and attracts great interest. Except moderating the increase of CO₂, the increasing consumption of fossil fuels also necessitate a renewable substitute. Biomasses are considered as promising resources to produce fuels and chemicals and researched as bio-renewable feedstocks.In the second chapter, in order to determine a proper relationship between the catalytic activity and physico-chemical properties of catalyst, six ceria-zirconia mixed oxides, which were prepared by different methods, were applied to catalyze the direct carboxylation of methanol to dimethyl carbonate（DMC）. Among these catalysts, the catalyst prepared through adipate complex-decomposition method exhibits the best performance. The proportion of Ce⁴⁺ in catalytic surface is the most important factor. Increasing the proportion of in surface can improve the catalytic activity.As one of important target chemicals in biomass program, 5-hydroxymethylfurfural（HMF）, due to its versatility, has attracted much attention. And in the third chapter, a series of phosphate-titanium immobilized MCM-48 catalysts were synthesized through impregnation method. Phosphate immobilization promotes the acidity of catalysts and enhances the yield of HMF. In the catalytic dehydration of glucose to HMF, the 40P-40T-MCM-48 possesses the best catalytic activity. Its surface Ti O₂ is a excellent Lewis acid catalyzing the transformation of glucose to fructose, and phosphate catalyzes the dehydration reaction as a Br?nsted acid. The synergy of TiO₂ and phosphate is the key of catalytic performance.