Bridging the structure-properties relationship of bimetallic catalysts is essential for the rational design of heterogeneous catalysts. Different from random alloys, intermetallic compounds (IMCs) present atomically-ordered structures, which is advantageous for catalytic mechanism studies. We used Pt-based intermetallic nanoparticles (iNPs), individually encapsulated in mesoporous silica shells, as catalysts for the hydrogenation of nitroarenes to functionalized anilines. With the capping-free nature and ordered atomic structure, PtSn iNPs show >99% selectivity to hydrogenate the nitro group of 3-nitrostyrene albeit with a lower activity, in contrast to Pt₃Sn iNPs and Pt NPs. The geometric structure of PtSn iNPs in eliminating Pt threefold sites hampers the adsorption/dissociation of molecular H₂ and leads to a non-Horiuti-Polanyi hydrogenation pathway, while Pt₃Sn and Pt surfaces are saturated by atomic H. Calculations using density functional theory (DFT) suggest a preferential adsorption of the nitro group on the intermetallic PtSn surface contributing to its high selectivity.

桥接双金属催化剂的结构-性质关系对于合理设计非均相催化剂至关重要。与无规合金不同，金属间化合物（IMC）具有原子序结构，这对于催化机理的研究是有利的。我们使用分别包裹在中孔二氧化硅壳中的基于Pt的金属间纳米颗粒（iNPs）作为将硝基芳烃氢化为功能化苯胺的催化剂。与Pt ₃ Sn iNPs和Pt NPs相比，PtSn iNPs具有无帽的性质和有序的原子结构，显示出对3-硝基苯乙烯的硝基进行氢化的选择性> 99％，尽管活性较低。消除Pt三重位点的PtSn iNPs的几何结构阻碍了分子H ₂的吸附/解离并导致非Horiuti-Polanyi加氢途径，而Pt ₃ Sn和Pt表面被原子H饱和。使用密度泛函理论（DFT）的计算表明，金属间PtSn表面上的硝基优先吸附，这有助于其高选择性。