The Study Of Catalytic Hydrogenation Performance For Biomass-derived Compound On Noble Metal/Carbon Nanotubes

As the energy crisis deepens, looking for renewable energy has been the priority of human. Biomass energy, which has the characteristics of rich resources, green environmental protection, is a kind of environmentally friendly new energy. However, biomass energy is full of oxygen, which means the down-stream products such as bio-oil and furfural have low stability. So people need to obtain higher quality bio-chemical production using some special craft. Hydrogenation by catalysts can increase the ratio of H/C efficiently, decrease the content of oxygen, and enhance stability of products, so Hydrogenation by catalysts has significant meaning for comprehensive utilization of biomass. In order to explore conditions about Hydrogenation by catalysts’ craft of biomass’ downstream mediators, people usually adopt simple Model Compound or platform compound to replace complex biomass’ downstream mediators and explore their experimental rules in the reaction of Hydrogenation by catalysts. In order to be able to model compounds under mild conditions and platform compound by catalytic hydrogenation, people usually focused on enhancing the catalyst activity to achieve their goals. However, a great number of reactions about Hydrogenation by catalysts use organic solvents, which are high-cost and toxic. On the other hand, some catalysts have low dispersity in organic solvents, which limits it application.In order to overcome those disadvantages mentioned above, this issue adopt CNTs over supported Ru and Au catalysts. Compounding nanoscale metal catalyst improve activity of catalyst, using special properties of the carbon nanotubes to further enhance the catalytic activity. We can adopt mixed solvent or pure water to overcame the consumption’s problem of organic solvent.Adopting impregnation method to prepare Ru/CNTs catalyst, we can measure Nanoparticles distribution which has small grain size through TEM Characterization. We looked hydrogenation reaction of vanillin which is model compound of Ru/CNTs catalytic and investigated effects of solvent, reaction temperature, reaction pressure, reaction time and other factors on the hydrogenation reaction of vanillin. Results are shown in mixed solvent between naphthane and deionized water. Under the condition of 150℃,1.0 MPa and 6 hours reaction time, using high concentrations of vanillin(5.9 mmol/40 m L) to catalyze hydrogenation reaction, vanillin conversion rate can achieve 100%. The Hydrodeoxygenation product’s selectivity can get to 94.7%. High catalytic activity and the presence of Pickering emulsion system make reaction process under relatively mild conditions, which can avoid vanillin coke, and thus the catalyst has good hydrogenation effect to biomass model compounds.By comparison between the different preparation methods, we identified that colloid immobilized Preparation of Au / CNTs is the highest catalytic activity of an Au catalyst. By TEM characterization of Au / CNTs, we can see a uniform distribution of Au nanoparticles, the average particle diameter of up to 3.79 nm. We looked at the Au/CNTs catalytic hydrogenation reaction of catalytic vanillin’s model compounds, investigated effects of solvent, reaction temperature, reaction pressure, reaction time and other factors on the hydrogenation reaction of vanillin. Results are shown that in the mixture of decalin and deionized water, 150 ℃, 1.0 MPa, reaction time 8 h conditions, vanillin conversion rate of 98.2%, hydrodeoxygenation selectivity up to 100%. High catalytic activity and the presence of Pickering emulsion system make reaction happen during mild conditions, avoid coke of vanillin. And thus the catalyst have good catalytic hydrogenation effect toward biomass model compounds.We further investigated the catalytic hydrogenation of Ru/CNTs to the platform compound furfural. In experiment, we investigated the effect of solvent, reaction temperature, reaction pressure, reaction time and other factors on the hydrogenation reaction of vanillin. The result has shown that using water as solvent, 3.55 mmol furfural, 100°C, 1.0 MPa, and 4 h reaction time, Furfural conversion rate of 77.6%, the target product selectivity 84.6% furfuryl alcohol. Mild conditions for furfural can avoid excessive side reactions. We can also use water as solvent to reduce the consumption of organic solvent, and thus the catalysts have a good catalytic hydrogenation effect toward biomass platform compound.