加氢脱氯在环境污染控制中的应用:负载及非负载型钯和镍催化剂性能的比较(英文)  

Application of Hydrodechlorination in Environmental Pollution Control:Comparison of the Performance of Supported and Unsupported Pd and Ni Catalysts

作　　者：Claudia AMORIM Mark A.KEANE 

机构地区：[1]Chemical Engineering,School of Engineering and Physical Sciences,Heriot-Watt University

出　　处：《催化学报》2011年第5期746-755,共10页

基　　金：supported by the National Science Foundation through Grant CTS-0218591

摘　　要：Catalytic hydrodechlorination(HDC)is an innovative means of transforming chlorinated waste streams into a recyclable product. In this study,the gas phase HDC of chlorobenzene(CB)has been studied over bulk Pd and Ni and((8±1)wt%)Pd and Ni supported on activated carbon(AC),graphite,graphitic nanofibers(GNF),Al2O3,and SiO2.Catalyst activation was examined by temperature-programmed reduction(TPR)analysis and the activated catalysts characterized in terms of BET area,transmission electron microscopy,scanning electron microscopy,H2 chemisorption/temperature-programmed desorption,and X-ray diffraction measurements.Metal surface area(1-19 m 2 /g), TPR,and H2 uptake/release exhibited a dependence on both metal and support.The Pd system delivered specific HDC rates that were up to three orders of magnitude greater than that recorded for the Ni catalysts,a result that we link to the higher H2 diffusivity in Pd.HDC was 100%selective over Ni while Pd also produced cyclohexane(selectivity<4%)as a result of a combined HDC/hydrogenation.Bulk Pd outperformed carbon supported Pd but was less active than Pd on the oxide supports.In contrast,unsupported Ni presented no measurable activity when compared with supported Ni.The specific HDC rate was found to increase with decreasing metal surface area where spillover hydrogen served to enhance HDC performance.Catalytic hydrodechlorination（HDC）is an innovative means of transforming chlorinated waste streams into a recyclable product. In this study,the gas phase HDC of chlorobenzene（CB）has been studied over bulk Pd and Ni and（（8±1）wt%）Pd and Ni supported on activated carbon（AC）,graphite,graphitic nanofibers（GNF）,Al2O3,and SiO2.Catalyst activation was examined by temperature-programmed reduction（TPR）analysis and the activated catalysts characterized in terms of BET area,transmission electron microscopy,scanning electron microscopy,H2 chemisorption/temperature-programmed desorption,and X-ray diffraction measurements.Metal surface area（1–19 m 2 /g）, TPR,and H2 uptake/release exhibited a dependence on both metal and support.The Pd system delivered specific HDC rates that were up to three orders of magnitude greater than that recorded for the Ni catalysts,a result that we link to the higher H2 diffusivity in Pd.HDC was 100%selective over Ni while Pd also produced cyclohexane（selectivity4%）as a result of a combined HDC/hydrogenation.Bulk Pd outperformed carbon supported Pd but was less active than Pd on the oxide supports.In contrast,unsupported Ni presented no measurable activity when compared with supported Ni.The specific HDC rate was found to increase with decreasing metal surface area where spillover hydrogen served to enhance HDC performance.

关 键 词：HYDRODECHLORINATION CHLOROBENZENE bulk palladium and nickel catalysts activated carbon graphite carbon nanofiber alumina silica spillover hydrogen 

分 类 号：X13[环境科学与工程—环境科学]