Pd Nanoparticles Anchored on Carbon Nanotubes/Covalent Organic Frameworks for Catalytic Ethanol Electrooxidation

Although there have been tremendous improvements in fabricating metal nanoparticle-functionalized two-dimensional (2D) heterogeneous materials, an effective strategy for loading ultrafine-sized metal nanoparticles with high catalytic performance and stability remains a challenge. Covalent organic frameworks (COFs) are a promising candidate template for the synthesis of decentralized metal nanomaterials with ultrafine diameters. In this study, an in situ grown nanocomposite (CNT-COF) of a COF on a carbon nanotube (CNT) has been prepared and applied in the synthesis of Pd nanoparticles with a narrow size distribution (denoted as CNT-COF-Pd). The 2D heterogeneous nanomaterial CNT-COF-Pd shows strong catalytic performance toward the ethanol oxidation reaction (EOR) in direct-ethanol fuel cells (DEFCs). The superior catalytic activity can be attributed to the strong coordination effect between the N atoms inside the cavities of the COF and Pd and the special electrical property of the CNT. We anticipate that such COF-supported ultrafine Pd nanoparticles will be a new 2D heterogeneous catalyst in DEFCs and other fields.