Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States.
J Am Chem Soc. 2021 Feb 24;143(7):2644-2648. doi: 10.1021/jacs.0c12278. Epub 2021 Feb 11.
We report the facile removal of surfactants from colloidally synthesized nanocrystals via ligand exchange with N-heterocyclic carbenes (NHCs). Subsequent protonation of the NHC ligands in acid efficiently cleans the nanocrystals' surface while preserving their uniform morphology and structure for catalysis. The broad efficacy of this strategy is validated using monodisperse Pt, Pd, and Au nanocrystals, each prepared with strongly bound phosphine stabilizers. The surface-activated nanocrystals exhibit significantly improved catalytic activities, superior to those obtained with other surface cleaning methods, as demonstrated in two centrally important electrochemical reactions (glycerol oxidation and CO reduction). This work highlights a new surface activation strategy for catalysis and other applications that enables the efficient use of well-defined nanocrystal libraries prepared by colloidal chemistry.
我们通过与 N-杂环卡宾（NHCs）的配体交换，从胶体合成的纳米晶体中轻松去除表面活性剂。在酸中，NHC 配体的质子化有效地清洁了纳米晶体的表面，同时保持了它们用于催化的均匀形态和结构。该策略的广泛有效性通过使用单分散 Pt、Pd 和 Au 纳米晶体得到了验证，这些纳米晶体均使用强结合膦稳定剂制备。表面活化的纳米晶体表现出显著提高的催化活性，优于通过其他表面清洁方法获得的活性，这在两个重要的电化学反应（甘油氧化和 CO 还原）中得到了证明。这项工作强调了一种新的用于催化和其他应用的表面活化策略，该策略能够有效地利用胶体化学制备的明确定义的纳米晶体库。
