Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States.
ACS Appl Mater Interfaces. 2023 Jun 21;15(24):29160-29169. doi: 10.1021/acsami.3c04087. Epub 2023 Jun 8.
Organic coatings on catalytic metal nanoparticles (NPs) typically hinder their activity due to the blocking of active sites. Therefore, considerable effort is made to remove organic ligands when preparing supported NP catalytic materials. Here, cationic polyelectrolyte coatings are shown to increase the catalytic activity of partially embedded gold nanoislands (Au NIs) toward transfer hydrogenation and oxidation reactions with anionic substrates compared to the activity of identical but uncoated Au NIs. Any potential steric hindrance caused by the coating is countered by a decrease in the activation energy of the reaction by half, resulting in overall enhancement. The direct comparison to identical but uncoated NPs isolates the role of the coating and provides conclusive evidence of enhancement. Our findings show that engineering the microenvironment of heterogeneous catalysts, creating hybrid materials that cooperatively interact with the reactants involved, is a viable and exciting path to improving their performance.
催化金属纳米粒子（NPs）表面的有机涂层通常会阻碍其活性，因为这会导致活性位点被封闭。因此，在制备负载型 NP 催化材料时，人们通常会花费大量精力去除有机配体。本文表明，与未涂层的相同金纳米岛（Au NIs）相比，带正电荷的聚电解质涂层会增加部分嵌入的金纳米岛（Au NIs）对阴离子底物的转移加氢和氧化反应的催化活性。涂层造成的任何潜在空间位阻都被反应活化能降低一半所抵消，从而实现了整体增强。与相同但未涂层的 NPs 的直接比较隔离了涂层的作用，并提供了增强的确凿证据。我们的研究结果表明，对多相催化剂的微环境进行工程设计，构建与反应物协同作用的杂化材料，是提高其性能的一种可行且令人兴奋的途径。
