As a joint investigation principle using experimental and theoretical approaches, we report that the anisotropic growth of Pt on Pd nanocubes significantly promotes the direct synthesis of hydrogen peroxide (H₂O₂) from hydrogen (H₂) and oxygen (O₂). The superior H₂O₂ productivity of the anisotropic Pd@Pt core@shell nanocrystals results from the enhanced H₂ conversion and the H₂O₂ selectivity compared to Pd and Pt. From the joint investigation, during the anisotropic growth of the Pd@Pt nanocrystals, high-index facets such as (2 1 0) are generated, and they provide numerous active sites for hydrogen dissociation. Notably, even the nano-catalyst is enclosed by Pt shell, the high-index facets are favorable for opening a new route for hydrogen dissolution into the Pd bulk lattices of the Pd@Pt nanocrystals, in which the dissolved hydrogen can react with chemisorbed O₂ over the nanocrystals to form H₂O₂. This mechanism is suggested by a hydrogen temperature programmed reduction (H₂-TPR) analysis, in situ transmission electron microscopy (TEM), and density functional theory (DFT) calculations. This study provides another option to improve the catalytic performance of core@shell nanocrystals via the generation of high-index facets through anisotropic growth of nanocrystals, in addition to the well-known strain and charge transfer effects. We expect that the anisotropic growth approach could be extended to other catalytic reactions.

作为使用实验和理论方法联合调查原理，我们报告的Pt对Pd的各向异性生长纳米立方体显著促进氢的直接合成过氧化（H ₂ ö ₂）选自氢（H ₂）和氧气（O ₂）。与Pd和Pt相比，各向异性的Pd @ Pt核@壳纳米晶体具有更高的H ₂ O ₂生产率，这归因于H ₂转化率和H ₂ O ₂选择性的提高。通过联合研究，在Pd @ Pt纳米晶体的各向异性生长过程中，高折射率面如（2 1 0）生成，并且它们提供了许多用于氢离解的活性位点。值得注意的是，即使纳米催化剂被Pt壳包裹，高折射率刻面也有利于开辟一条新的途径将氢溶解到Pd @ Pt纳米晶体的Pd本体晶格中，其中溶解的氢可以与化学吸附的O反应₂在纳米晶体上形成H ₂ O ₂。氢气温度程序设定的还原（H ₂-TPR）分析，原位透射电子显微镜（TEM）和密度泛函理论（DFT）计算。这项研究提供了另一种选择，即通过众所周知的应变和电荷转移效应，通过各向异性生长纳米晶产生高折射率的晶面，从而提高了核壳纳米晶的催化性能。我们期望各向异性生长方法可以扩展到其他催化反应。