Synthesis of Ultrafine and Highly Dispersed Metal Nanoparticles Confined in a Thioether-Containing Covalent Organic Framework and Their Catalytic Applications

Abstract

Covalent organic frameworks (COFs) with well-defined and customizable pore structures are promising templates for the synthesis of nanomaterials with controllable sizes and dispersity. Herein, a thioether-containing COF has been rationally designed and used for the confined growth of ultrafine metal nanoparticles (NPs). Pt or Pd nanoparticles (Pt NPs and Pd NPs) immobilized inside the cavity of the COF material have been successfully prepared at a high loading with a narrow size distribution (1.7 ± 0.2 nm). We found the crystallinity of the COF support and the presence of thioether groups inside the cavities are critical for the size-controlled synthesis of ultrafine NPs. The as-prepared COF-supported ultrafine Pt NPs and Pd NPs show excellent catalytic activity respectively in nitrophenol reduction and Suzuki-Miyaura coupling reaction under mild conditions and low catalyst loading. More importantly, they are highly stable and easily recycled and reused without loss of their catalytic activities. Such COF-supported size-controlled synthesis of nanoparticles will open a new frontier on design and preparation of metal NP@COF composite materials for various potential applications, such as catalysis and development of optical and electronic materials.

Pore Surface Engineering of Covalent Triazine Frameworks@MoS2 Electrocatalyst for the Hydrogen Evolution Reaction

“…Notably,t he lattice spacing of MoS 2 in the doping composites is slightly larger than literature report( 0.62 nm), which is attributed to ion intercalation. [28][29][30][31][32][33][34][35] The nitrogen-containing triazine unit in the CTF skeleton can activate the electrons around the carbon,w hich will lead to an outstanding electrochemical performance. [27] Meanwhile, interplanars pacing of 0.27 nm is in accordance with the (1 00) Based on the above,C TFs@MoS 2 -X have ac rystal p-conjugated stacking architecture and hierarchical meso-and micropores in one hybrid system;t his fine structure is facile for fast p-electron hopping,m ass transfer,a nd confinement of the MoS 2 nanoparticles to facilitate large-particle growth.…”

Opportunities of Covalent Organic Frameworks for Advanced Applications

“…[49] A set of control experiments revealed that the crystallinity of the COF support and the presence of thioether groups inside the cavities are critical for the size-controlled synthesis of ultrafine NPs. Zhang and co-workers showed how COFs display the right combination of properties to serve as ideal host materials for size-controlled synthesis of nanoparticles, as demonstrated by entrapping Pt and Pb nanoparticles onto a thioether-containing COF.…”

Nitrogen‐Rich Porous Organic Polyamines for Stabilization of Highly Dispersed Metal Nanoparticles and Catalytic Application

“…Heterogeneous and homogeneous catalysts, especially metal nanoparticles (NPs) supported catalysts with excellent catalytic performance have attracted extensive interest in the last decade . Metal NPs exhibit excellent catalytic activity in organic reactions, such as nitro reduction, hydrogenation, CH activation, and coupling reactions .…”