| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 100 === Light harvesting complex (LHCⅡ) which was extracted from green plants could enhance the visible light absorbance. It gave an idea that attaching the LHCⅡmaterial to the surface of TiO2 series catalysts might get a good efficiency in reducing CO2. In this research, we prove the concept with following experiments. Two kinds of photo catalysts, TiO2:Rh and TiO2:Rh-LHCⅡwere used to reducing CO2 in slurry system. After six hours reaction, the yield of CO could reach 3.43 μmol/g, acetaldehyde could reach 19.2μmol/g and methyl formate could reach 1.53μmol/g with TiO2:Rh-LHCⅡcatalysts which was nine to ten times enhancement in acetaldehyde. Four times increase in methyl formate compared to TiO2:Rh. Use FTIR and APCI/MS analysis to investigate the mechanism of the photo reaction.
The second part of the research was to enhance the efficiency of CO2 reduction with hydrogen. Hydrogen involving in the photo reaction could give a smaller ΔG value comparing to which was without hydrogen. In the research, we dedicated ourselves to finding a catalyst which could utilize hydrogen to reduce CO2 efficiently. We loaded rhodium and platinum by impregnation and photodeposition method on CuAlGaO4 respectively. Some groups prove that the two kinds of cocatalyst have better efficiency in utilizing hydrogen. CuAlGaO4 was chosen as the photocatalyst which was synthesized by solid state method. The result showed that the yield of methanol could reach 7.38μmol/g and the yield of ethanol could reach 9.36μmol/g after six hours photo reaction. What we expect was not only to reduce CO2 but also to transform it to useful fuels. FT-IR analysis was to check the result of the photoreaction and gave a possible reaction mechanism.
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