Vapor‐Phase Synthesis of Electrocatalytic Covalent Organic Frameworks

Abstract

The inability to process many covalent organic frameworks (COFs) as thin films plagues their widespread utilization. Herein, a vapor‐phase pathway for the bottom‐up synthesis of a class of porphyrin‐based COFs is presented. This approach allows integrating electrocatalysts made of metal‐ion‐containing COFs into the electrodes’ architectures in a single‐step synthesis and deposition. By precisely controlling the metal sites at the atomic level, remarkable electrocatalytic performance is achieved, resulting in unprecedentedly high mass activity values. How the choice of metal atoms, i.e., cobalt and copper, can determine the catalytic activities of POR‐COFs is demonstrated. The theoretical data proves that the Cu site is highly active for nitrate conversion to ammonia on the synthesized COFs.

Carbon Dioxide Adsorption within Porous Porphyrin Networks

“…This value was notably increased to 51% for ZnPOR-COF-Py, indicating a significant improvement attributed to including pyridine pulse during the oxidative polymerization. This trend is similar to our previous observation of POR-COF-Py and CuPOR-COF-Py crystallinity prepared using comparable conditions . TEM examination, portrayed in Figure C, further substantiates these findings, unveiling well-defined lattice patterns with crystalline domains as large as 20 nm within the deposited films, characterized by consistent orientations.…”

“…This trend is similar to our previous observation of POR-COF-Py and CuPOR-COF-Py crystallinity prepared using comparable conditions. 14 TEM examination, portrayed in Figure 2C, further substantiates these findings, unveiling well-defined lattice patterns with crystalline domains as large as 20 nm within the deposited films, characterized by consistent orientations. Correspondingly, the TEM analysis of POR-COF-Py and CuPOR-COF-Py (demonstrated in Figure S7) present aligned lattice structures, indicative of their inherent crystalline nature.…”

“…To deposit thin films of MPOR-COFs, porphyrin molecules, namely 5,10,15,20-tetra(4-aminophenyl) porphyrin (TAPP) or its transition-metal complexes (M-TAPP, where M = Zn 2+ , Cu 2+ ), were prepared, purified, and employed as the primary precursors. The preparation procedure for TAPP and Cu-TAPP is outlined in our prior publication, 14 and the procedure for Zn-TAPP is provided in Supporting Information, Section 1. The corresponding structural characterization and thermal stability of Zn-TAPP are provided in Figures S1−S3.…”

“…The plausible reaction mechanism for MPOR-COFs formation is discussed in our previous publication. 14 Briefly, the amine group at the meso position forms an adduct with SbCl 5 , directing to subsequent two-electron oxidation. This oxidation leads to forming a radical cation (M-TAPP .+ ) from M-TAPP.…”

“…The resulting MPOR-COF synthesized with a pyridine pulse was denoted as POR-COF-Py, ZnPOR-COF-Py, and CuPOR-COF-Py, respectively. The plausible reaction mechanism for MPOR-COFs formation is discussed in our previous publication . Briefly, the amine group at the meso position forms an adduct with SbCl 5 , directing to subsequent two-electron oxidation.…”