Copper/Ceria Catalysts for Water-Gas Shift Reaction

• Main Authors: Yi-tin Hu, 胡義亭
• Other Authors: Ien-Whei Chen
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/65573981284489545599

碩士 === 大同大學 === 化學工程學系(所) === 92 === In the methanol steam-reforming reaction, there are small quantities carbon monoxides, and the water-gas shift reaction is the method which is applies recently to converse large amount of carbon monoxide. This research is to develop, Cu-series catalyst with high performance of removing carbon monoxide at low temperature (200 ℃~280 ℃). In this research, silicon dioxide (SiO2) was used as carrier, treats as the active metal by the Cu and Ce, contains the different proportion active metal impregnated on the carrier, then they were calcined at the high temperature of 500 ℃. After being reduced, the catalysts possessed the best efficiency of removing CO. The characteristic analyses of the Cu-series catalysts were performed by TGA, TPR, TPO, XRD and ICP. The water-gas shift reaction was carried out in the fixed-bed reaction: under the circumstances of the hydrogen-rich atmosphere, a gas containing small quantity of CO for simulating the trailing gas of fuel cell passed through the reactor, and before the reaction took place, the catalysts were reduced with hydrogen; besides, comparisons of the active metals of oxidization state with the active metals of reduction state were made, so as to find out the differences in efficiencies of removing CO and the optimal proportions of catalysts. The experimental result showed that the active metal Ce increased on the Cu/SiO2 carrier promoted the metal dispersion and particle diameters of active metal copper was smaller. From the reduction peak diagrams of TPR, it could be known that the higher was the active metals content in the catalyst, the easier was on the carrier surface to from large grains of oxidized copper, and the higher was the reduction temperature, showing that when the catalysts carried out WGSR, the activities were poorer. During WGSR, added ceria in Cu-series catalyst, its catalyst activity had not added the ceria in Cu-series catalyst is better than; Using SiO2 was the support, when the Cu content reached to 25 wt%, the CO removing percentage at 250 ℃ could reach 92%; When has not added the ceria the catalyst, the Cu content reached to 25 wt%, the CO removing percentage at 250 ℃ could reach 75%.