Two methods, incipient wetness impregnation (IM) and adsorptionprecipitation (AP) were used to prepare alumina-supported Ru catalysts. Using the selective hydrogenation of dimethyl maleate as a probe reaction, the obtained results demonstrated an enhanced catalytic activity with the AP method as compared to the IM technique. It was also found that higher hydrogenation activity was obtained with samples that were directly activated in H2 flow. In contrast, the activity decreased seriously when the catalyst samples were subjected to a calcination pretreatment prior to activation with H2 reduction, especially for the IM technique. Additional catalytic testings on Ru/Al(AP)-R with chlorine addition demonstrated that the catalytic activity was greatly decreased, suggesting that chlorine has a negative effect on the hydrogenation behaviors of Ru. Combined with the characterization results of XRD, H2-TPR, H2-TPD and XPS, the advantage of the AP method can be summarized as the following: this technique effectively eliminates chlorine, thus resulting in a better dispersion of Ru species and decreasing the negative influence of chlorine on Ru. A superior Ru/alumina catalyst can be obtained with the AP followed by direct activation with H2 reduction.
Chinese Acad Sci, Xinjiang Tech Inst Phys & Chem, Urumqi 830011, Peoples R China;Univ Chinese Acad Sci, Beijing 100000, Peoples R China;Chinese Acad Sci, Inst Coal Chem, Taiyuan 030000, Peoples R China
Wang, Lei,Abudukelimu, Nuermaimaiti,Ma, Yubo,et al. Enhanced Ru/Alumina catalyst via the adsorption-precipitation (AP) method for the hydrogenation of dimethyl maleate[J]. REACTION KINETICS MECHANISMS AND CATALYSIS,2014,112(1):117-129.