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Title of Talk Shape Control of Bimetallic Nanocatalysts for High Efficiency EnergyConversion
Abstract Metallic nanocatalysts are indispensable for various energy conversion reactions and processes. The catalytic performances of metallic nanocatalysts can be tuned and maximizedthrough the control over the factors such as surface atomic arrangement, charge transfer and lattice compression or extension of the bimetallic nanostructures.1-2 One way to investigate the catalytic effects of those parameters is to use shape-controlled bimetallic nanocrystals exposing well-defined facets with given compositions as model catalysts. More recently, our group has been investigating how different small molecules induce Pt based nanocrystals to expose particular facets during the solution synthesis, and their shape dependent electro-catalytic properties toward methanol oxidation reaction (MOR). It was shown that, in the synthesis of Pt-Pd alloy nanocrystals, C2O42− ions could stabilize {111} facets and be used to synthesize Pt-Pd nano-tetrahedrons. Br− and I− ions could stabilize {100} facets andbe used to synthesize Pt-Pd nanocubes. It was also proved that the catalytic activity of Pt-Pd bimetallic nanocrystals towards MOR is strongly correlated with their exposing facets.3 Decreasing reduction rate of metal precursors facilitates the formation of multi-twinned nuclei. Thus, five-fold-twinned Pt-Pd alloy nano-icosahedrons could be prepared under low reduction rate. The twinned defects in Pt-Pd nano-icosahedrons endowed them with higher catalytic activity towards MOR than that of Pt-Pd nano-tetrahedrons.4 Using underpotential deposition and galvanic replacement reaction, we also prepared Pt-Cu and Pt-Pd-Cu alloy concave nanocubes through one-pot synthetic procedure. These concave nanocubes expose high-index facets, and exhibit higher catalytic activity towards MOR than their cubic counterparts.5
References: 1. Stamenkovic, V. R.; Mun, B. S.; Arenz, M.; Mayrhofer, K. J. J.; Lucas, C. A.; Wang, G. F.; Ross, P. N.; Markovic, N. M. Nat. Mater.2007, 6, 241 2. Strasser, P.; Koh, S.; Anniyev, T.; Greeley, J.; More, K.; Yu, C.; Liu, Z.; Kaya, S.; Nordlund, D.; Ogasawara, H.; Toney, M. F.; Nilsson, A. Nat. Chem.2010, 2, 454 3. Yin, A. X.; Min, X. Q.; Zhang, Y. W.; Yan, C. H. J. Am. Chem. Soc.2011, 133, 3816 4. Yin, A. X.; Min, X. Q.; Zhu, W.; Wu, H. S.; Zhang, Y. W.; Yan, C. H. Chem. Commun.2012, 48, 543 5. Yin, A. X.; Min, X. Q.; Zhu, W.; Liu, W. C.; Zhang, Y. W.; Yan, C. H. Chem. Eur. J.2012, 18, 777 |
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Yawen Zhang, Professor
College of Chemistry and Molecular Engineering Peking University, Beijing, 100871, China e-mail: ywzhang@pku.edu.cn
Profile. YawenZhangobtained his B. Sc. Degree, M. Sc. Degree, and Ph. D. Degree from Peking University in 1988, 1994 and 1997, respectively, and did postdoctoral research in State Key Laboratory of Rare Earth Materials Chemistry and Applications of Peking University during 1998-2000, and had been a visiting scholar in Department of Chemistry of University of California at Berkeley and Lawrence Berkeley National Laboratory during 2006-2008. He is a full professor and principle investigator at College of Chemistry and Molecular Engineering of Peking University. The research interests of his group are focusing on the rational design, controllable synthesis, ordered assembly, catalytic properties and structure-function relationships of rare earth & noble metal nanostructures. He has published more than 100 papers in peer-reviewed scientific journals and was a Winner of National Science Fund for Distinguished Young Scholars in 2010.
Selected Publications 1. Gu, J.; Zhang, Y.-W.; Tao, F.Chem. Soc. Rev. 2012, 41, 8050 2. Yin, A.-X.; Liu, W.-C.;Ke, J.;Zhu,W.;Gu, J.;Zhang,Y.-W.;Yan, C.-H. J. Am. Chem. Soc. 2012,134, 20479 3. Ding,Y.;Gu,J.;Zhang,T.;Yin,A.-X.; Yang,L.;Zhang, Y.-W.; Yan, C.-H.J. Am. Chem. Soc.2012, 134, 3255 4. Yin,A.-X.; Min, X.-Q.;Zhang, Y.-W.; Yan, C.-H.J. Am. Chem. Soc.2011, 133, 3816 5. Ding,Y.; Gu,J.;Ke,J.; Zhang, Y.-W.; Yan, C.-H.Angew. Chem. Int. Ed. 2011, 50, 12330 |
