Preparation Of Doping Cerium Oxide Nanoparticles Within Nonaqueous Microemulsion Systems And Their Application

As a clean alternative fuel, methanol gasoline has been widely applied in Shanxi, Shannxi, Guizhou, and Jiangsu provinces. However, some researches found that the higher latent heat of vaporization of methanol induced combustion under low temperature, and the reduction in exhaust gas temperature promoted the emission of formaldehyde. For methanol/diesel fuel, some papers have reported that the emission of CO, HC, and PM was increased while the smoke intensity was decreased. Up to the date, there is no effective solution for the exhaust emission of methanol gasoline.From the perspective of promoting power efficiency and reducing the exhaust emission, the components of nonaqueous microemulsion was identified. The nonaqueous microemulsion was composed of methanol/ formamide as polar phase, n-octane as oil phase, and AEO3 as surfactant. The effect of concentrations of Ce3+, OH-, Cu2+ and Zr4+ on the microemulsion phase behavior was also investigated. The nanoparticles of cerium oxide with Cu, Zr doping were prepared and applied in 90# gasoline and M15 methanol gasoline. The power performance, fuel economy performance, and the exhause emission of oil with nanoparticles added were investigated by platform experiments. The main results are as follows:1. Nonaqueous microemulsions with polar nonaqueous solvents replaced the water in the common microemulsion, which have a silimar micro-structrue as that of common microemuslion. Nonaqueous microemulsion were rarely studied, even some researches strongly indicated these polar organic solvent-hydrocarbon dispersions to be molecular solutions without well-defined microemulsion droplets. In the paper, the microemulsion phase diagram and the mechanism of surfactants, methanol/formamide, and n-octane forming microemulsion werer investigated. Moreover, the methyl orange (MO) and methylene blue (MB) were used as absorption probes. The microstructure of nonaqueous microemulsions was probed with uv-vis spectroscopy measurements. The results indicated that an n-octane continuous structure with formamide nano-droplets formed in formamide/AEO3/n-octane system.2. Microemulsions are thermodynamically stable, transparent and isotropic liquid mediums with nanosized "water pools" dispersed in a continuous phase, which have been widely used to prepare stable colloidal dispersions of different types of nanoparticles. However, there are only few publications on formation of nanoparticles from nonaqueous microemulsions. Although nonaqueous microemulsion showed some advantages on simple post-processing deal, the use in water-sensitive environments, the general process, mechanism, synthesis rules were rarely reported. In the paper, the microstructure of nonaqueous microemulsion containing 0.075M NaOH and 0.025M Ce (NO3)3 were investigated by DLS measurements and conductivity measurements. The results showed that formamide systems have similar microstructure to aqueous microemulsions and bi-continuous structure was shown in methanol system. Moreover, cerium oxide and Zr, Cu doping nanoparticles were synthesized by mixing formamide/AEO3/ n-octaneoil continuous microemulsion containing cerium nitrate and sodium hydroxide. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the phase and morphology of synthesized nanoparticles. It was found that the synthesis mechanism within nonaqueous microemulsions were similar with that of aqueous microemulison. The micro-structure of microemulsion affected the size distribution and the morphology of nanoparticles. The polarity of methanol/formamide influenced the morphology of nanoparticles obviously. Furthermore, the morphology of nanoparticles induced the bi-continuous structure or nano polar solvent pool formed in these nonaqueous systems.3. As a waterless system, nonaqueous microemulsion could not induce phase separation in methanol gasoline. Inspired by the phenomena, nonaqueous microemulsion was applied to prepare Zr, Cu doping cerium oxide nanoparticle. With the high-speed centrifuge, doping cerium oxide nanoparticles were added in M15 methanol gasoline with 100 ppm for 30 days, and no obvious aggregations were found. This method overcomes the disadvantages of the relatively complicated process in common microemulsions, such as washing, centrifuge, dry and so on, which is a more economic and easy method. Moreover, platform experiments for the 90# gasoline and M15 methanol gasoline with 100 ppm cerium oxide and Zr, Cu doping nanoparticle added were preceded. As the results shown, the content of CO, HC, PM, and NOx in the exhausted emission of 90# gasoline/M15 were markedly decreased with the nanoparticles added. All the gasoline with different additives showed well external characteristics and power performance, and the output torque were promoted at higher engine speed. This technics has been successfully applied in the methanol gasoline production of Shanxi Aidec Science and Technologies Co. as a key technology. The technology progeny has been certificated by the Shanxi science and technology department, and the certificate of identification is domestic advanced level (No.091206; No.091207). Furthermore, the technics has inquiry China Invention Patent (CN 101591576A).