Studies of Hydrogen Production from Ethanol over Pt-Ru Supported Catalysts

• Main Authors: Bi,Jia-Lin, 畢家麟
• Other Authors: Wang,Chen-Bin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/66928737903013366105

博士 === 國防大學中正理工學院 === 國防科學研究所 === 95 === Highly dispersed supported PtRu catalysts (dPtRu < 5 nm) on ZnO, CeO2, ZrO2, Al2O3, NiO, and Co3O4 supports were prepared by impregnation method. Evaluation of catalytic activities and products distribution of supported PtRu catalysts toward ethanol reforming reactions were tested in a fixed bed reactor. The catalytic activities of three processes of ethanol reforming were compared: steam reforming of ethanol (SRE), partial oxidation of ethanol (POE) and oxidative steam reforming of ethanol (OSRE). The aim of this study is focused on the design of ethanol reforming catalysts to produce hydrogen at low-temperature with higher ethanol conversion (CEtOH), hydrogen yield (YH2) and lower CO distribution. The results showed that the SRE required higher temperature (TR > 500 ℃) to achieve 100% ethanol conversion, however, as adding oxygen to lower the TR for POE and OSRE (TR < 300 ℃). Based on the evaluation of catalysts, we got the optimized ratios of O2/EtOH and H2O/EtOH for OSRE were 0.44 and 4.85. Also, the kinds of support can affect the hydrogen yield and CO distribution on the supported PtRu catalysts. Among the six catalysts, PtRu/CeO2 and PtRu/ZrO2 exhibited the higher ethanol conversion, hydrogen yield and lower contamination of CO. Both catalysts got a dried hydrogen-rich gas (HRG) composed with high hydrogen (~ 70 %) and low CO (~ 2.47 %) contamination. Under the H2O/EtOH = 4.85 and O2/EtOH = 0.44 condition, the OSRE over PtRu/CeO2 catalyst was completely converted to get 2.28% CO and 4.08 mol H2/mol EtOH; the OSRE over PtRu/ZrO2 catalyst was completely converted to get 2.47% CO and 4.65 mol H2/mol EtOH. The composition of HRG is suitable to feed hydrogen fuel cell after the stage of CO removal by preferential oxidation.