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Regulation of Strong Metal-Support Interaction by Alkaline Earth Metal Salts |
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| Authors: | Guanghao Qiu Dr. Qijun Pei Dr. Yang Yu Dr. Zijun Jing Jintao Wang Prof. Teng He Prof. Ping Chen |
| Affiliation: | 1. Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 P. R. China University of Chinese Academy of Sciences, Beijing, 100049 P. R. China These authors contributed equally.;2. Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 P. R. China These authors contributed equally.;3. Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 P. R. China;4. Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 P. R. China University of Chinese Academy of Sciences, Beijing, 100049 P. R. China |
| Abstract: | Classical strong metal-support interaction (SMSI) is of significant importance to heterogeneous catalysis, where electronic promotion and encapsulation of noble metal by reducible support are two main intrinsic properties of SMSI. However, the excessive encapsulation will inevitably hamper the contact between active sites and reactant, leading to reduced activity in catalysis. Herein, alkaline earth metal salts are employed to depress the encapsulation of Ru nanoparticles in Ru/TiO2 catalyst in the present study. Thermodynamic calculation, transmission electron microscopy (TEM) and chemisorption results show that the alkaline earth metal salts could successfully prevent the migration of TiO2-x overlayer to Ru nanoparticles in Ru/TiO2 catalyst via in situ formation of titanates, resulting in high exposure of active metal. Meanwhile, X-ray photoelectron spectroscopy (XPS) and hydrogen temperature-programmed reduction (H2-TPR) results reveal that an even stronger electron donation from the reduced support to Ru nanoparticles is achieved. As a result, the alkaline earth metal salts-doped Ru/TiO2 catalysts exhibit superior activity in catalytic hydrogenation of aromatics, which is in contrast to the pristine Ru/TiO2 catalyst that shows negligible activity under the same conditions due to the excess encapsulation of Ru nanoparticles in Ru/TiO2 catalyst. |
| Keywords: | strong metal-support interaction alkaline earth metal salt suppression of encapsulation electron donation hydrogenation |