Regulation of Electrocatalytic Behavior by Axial Oxygen Enhances the Catalytic Activity of CoN₄ Sites for CO₂ Reduction

Abstract

Recent studies have found that the existence of oxygen around the active sites may be essential for efficient electrochemical CO2‐to‐CO conversion. Hence, this work proposes the modulation of oxygen coordination and investigates the as‐induced catalytic behavior in CO2RR. It designs and synthesizes conjugated phthalocyanine frameworks catalysts (CPF‐Co) with abundant CoN4 centers as an active source, and subsequently modifies the electronic structure of CPF‐Co by introducing graphene oxide (GO) with oxygen‐rich functional groups. A systematic study reveals that the axial coordination between oxygen and the catalytic sites could form an optimized O‐CoN4 structure to break the electron distribution symmetry of Co, thus reducing the energy barrier to the activation of CO2 to COOH*. Meanwhile, by adjusting the content of oxygen, the proper supports can also facilitate the charge transfer efficiency between the matrix layer and the catalytic sites. The optimized CPF‐Co@LGO exhibits a high TOF value (2.81 s−1), CO selectivity (97.6%) as well as stability (24 h) at 21 mA cm−2 current density. This work reveals the modulation of oxygen during CO2RR and provides a novel strategy for the design of efficient electrocatalysts, which may inspire new exploration and principles for CO2RR.

Covalent porous catalysts for electrochemical reduction of CO2

“…Electrochemical results show that NiPPc/CNT exhibits a high current density of ∼300 mA cm −2 for CO 2 RR with a CO selectivity of 99.8%. A similar research study was conducted by Zang et al , 147 by introducing graphene oxide (GO) to modify the charge density distribution of CoPc (Fig. 13f).…”

“…Structural characterization of CPF-Co@GO, CPF-Co@LGO, and CPF-Co@rGO, (g) the high-resolution C 1s XPS spectra, (h) Co K edge XANES spectra, and (i) Co K-edge FT of the EXAFS spectra. 147 terns and Raman spectra indicate the successful synthesis of coaxial NiPPc/CNT (Fig. 13b and d).…”

“…(f) Schematic illustration of the CPF-Co@GO/LGO/rGO hybrid preparation and application to electrocatalytic CO 2 to CO conversion. Structural characterization of CPF-Co@GO, CPF-Co@LGO, and CPF-Co@rGO, (g) the high-resolution C 1s XPS spectra, (h) Co K edge XANES spectra, and (i) Co K-edge FT of the EXAFS spectra 147.…”

Reprogramming the Microenvironment of Cobalt Phthalocyanine by a Targeted Multifunctional π-Conjugated Modulator Enables Concerted CO2 Electroreduction

“…12−14 For example, cobalt phthalocyanine (CoPc) exhibits a unique catalytic selectivity for converting CO 2 to CO and has a low reaction barrier for the catalytic rate-determining step (RDS) (*CO 2 → *COOH intermediate). 15,16 What cannot be ignored, however, are the characteristics of CoPc that greatly inhibit its catalytic capability. Besides the intrinsic poor conductivity, the strong π−π interaction between CoPc molecules generally brings the molecular stacking aggregation to mask the active sites seriously.…”

Crucial Effect of Surface Oxygen Species on CO2 Electroreduction Performance in Ti@Cu Single Atom Alloys

“…metal catalysts, metal-oxide, carbon material, MOFs, and so on. [13][14][15][16][17][18] However, the intricate proton-coupled electron transfer (PCET) process in eCO2RR, affected by catalyst characteristics and reaction variables, constrains the ability of these technologies to produce specific products with precision, posing a challenge to their commercial viability. [19] For instance, in specific conditions, the surface of a Cu catalyst can yield as many as 16 different products during the eCO2RR process.…”