科研之友
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摘要
Understanding the effects of catalyst surface structure on a catalytic reaction is of fundamental importance in catalysis chemistry. Herein, a series of Pt-on-Au (Pt-m,boolean AND Au, m refers to the atomic Pt/Au ratio; Au size: 3.2 +/- 0.4 nm) nanostructures with Pt dispersion in the range of 38% to 100% are used to study the structure sensitivity of the hydrogenation reactions of 1,3-butadiene and ethylene, respectively. The specific catalytic rates for both reactions are observed to increase with a decrease in the Pt dispersion or increasing m in Pt,<^>Au, demonstrating the structure-sensitive nature of both reactions over the Pt-m boolean AND Au nanostructures. These observations strongly contrast with the structure insensitivity of the same reactions over our deliberately prepared counterpart Pt/SiO2 catalysts with Pt dispersion varying in 6%similar to 100% and also those documented in literature and thus identify a distinct feature of Pt in the Pt-m boolean AND Au nanostructures. Characterization results from 'CANES spectroscopy and DRIFTS of adsorbed CO show that the variation of Pt dispersion or m in Pt-m boolean AND Au resulted in systematical changes in the electronic property of Pt, which uncover the nature of the structure sensitivity. These findings would have important implications for better understanding the dimension and richness of the structure-sensitivity concept and the features of Pt-on-Au nanostructures in catalysis and nanomaterial chemistry, as well as its related fields.
