Microreactors present innovative solutions for problems pertaining to conventional reactors and therefore have seen successful application in several industrial processes. Yet, its application in heterogeneously catalyzed gas–liquid reactions has been challenging, mainly due to the lack of an easy and flexible methodology for catalyst incorporation inside these reactors. Herein, we report a facile technique for obtaining small (<2 nm) and well-distributed catalytic nanoparticles on the walls of silica-coated capillaries, that act as micro(channel) reactors. These particles are formed in situ on the reactor walls using polyelectrolyte multilayers (PEMs), built by layer-by-layer self-assembly. Manipulating the PEMs’ synthesis condition gives easy control over metal loading, without compromising on particle size. Both monometallic (Au and Pd) and bimetallic (AuPd) nanoparticles were successfully obtained using this technique. Finally, these catalytic microreactors were found to exhibit exceptional activity for the direct synthesis of hydrogen peroxide from H₂ and O₂.

中文翻译：

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使用聚电解质多层膜直接合成H ₂ O ₂在毛细管微反应器内轻松合成催化AuPd纳米颗粒

微型反应器为与常规反应器有关的问题提供了创新的解决方案，因此已成功应用于多种工业过程中。然而，其在非均相催化气液反应中的应用一直具有挑战性，这主要是由于缺乏在这些反应器内掺入催化剂的简便灵活的方法。在这里，我们报告了一种简便的技术，可在二氧化硅涂层的毛细管壁上获得小的（<2 nm）且分布均匀的催化纳米颗粒，用作微通道反应器。这些颗粒是使用聚电解质多层（PEM）在反应器壁上原位形成的，而PEM是通过逐层自组装而构建的。操纵PEM的合成条件可轻松控制金属负载，而不会影响粒度。使用该技术成功获得了单金属（Au和Pd）和双金属（AuPd）纳米颗粒。最后，发现这些催化微反应器对于由H直接合成过氧化氢表现出优异的活性。₂和O ₂。