Constructing Porous Carbon Electrocatalysts from Cobalt Complex-Decorated Micelles of Mesoporous Silica for Oxygen Reduction/Evolution Reaction

Abstract

The construction of a porous carbon structure with a high specific surface area is conducive to enhanced electrocatalytic activity due to the accessibility of active sites and improvement of the mass transfer. Herein, we explored the possibility of using micelles of mesoporous silica (MCM-48) as the carbon source to generate porous carbon under the confinement of MCM-48 channels. The complexes formed by Co2+ and 4,4′-bipyridine were in situ incorporated into the micelles to derive Co-related active sites (Co-N x , Co, and Co3O4) for catalyzing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). After pyrolysis in the N2 atmosphere and subsequent removal of the MCM-48 skeleton, the target porous carbon electrocatalyst was obtained, which exhibited promising performance for both ORR and OER and has great potential as the cathode material for Zn–air battery application. This work not only confirms the effectiveness of using the micelles of MCM-48 as the carbon source for preparing the porous carbon materials, but also provides a new platform for design and synthesis of structurally controllable materials for energy-related electrocatalytic applications.

An Ultrastable Bifunctional Electrocatalyst Derived from a Co2+-Anchored Covalent–Organic Framework for High-Efficiency ORR/OER and Rechargeable Zinc–Air Battery

“…On account of the promising ORR/OER activity of CoO x @NC-800, the potential gap (Δ E = E 10 – E 1/2 ) between the E 1/2 of ORR and E 10 of the OER was used to assess its bifunctional electrocatalytic performance. As shown in Figure d, the CoO x @NC-800 presents a Δ E of 0.70 V, the smallest among its counterparts (0.86 V of CoO x @NC-800 and 0.87 V of CoO x @NC-800) and lower than many of the recently reported bifunctional electrocatalysts (Figure f). ,,,− Because better performance originates from a smaller Δ E value, CoO x @NC-800 shows great potential as the reversible oxygen electrode material.…”

Silica‐Derived Nanostructured Electrode Materials for ORR, OER, HER, CO2RR Electrocatalysis, and Energy Storage Applications: A Review**

“…Schematic illustration of (a) The preparation process of MPC@Cobi. [51] Reproduced (adapted) from ref. [51] Copyright (2021), with permission from American Chemical Society.…”

“…[51] Reproduced (adapted) from ref. [51] Copyright (2021), with permission from American Chemical Society. (b) Fabrication of various Fe 2 O 3 nanoparticles confined in the shell of N-doped carbon hollow sphere.…”

Compositional Engineering of Co(II)MOF/Carbon-Based Overall Water Splitting Electrocatalysts: From Synergistic Effects to Structure–Activity Relationships

“…21,22 However, the high price, low abundance, and worse chemical stability of precious metals restrict their large-scale commercial use. 23,24 In recent years, those non-noble metal-based catalysts for electrolytic water decomposition with eminent electrochemical activity and stability have captured much more attention and can perfectly replace noble metal catalysts. 25,26 Metal−organic frameworks (MOFs), also called porous coordination polymers, are made up of organic ligands with adjustable structures and metal ions/metal clusters through coordination bonds.…”

“…The hydrogen evolution reaction (HER) occurs at the cathode, and the oxygen evolution reaction (OER) occurs at the anode from the electrochemical hydrolysis reaction. − Despite the fact that electrochemical water decomposition is an effective method to produce H 2 with zero carbon emissions, the practical application of large-scale hydrogen production is hindered due to the excessive overpotential. − Highly efficient electrocatalysts of the OER and HER are exploited to overcome the overpotential generated in this process and minimize energy consumption throughout the process. − Traditionally, the precious metal Pt is still the most predominant electrocatalyst toward the HER, and IrO 2 and RuO 2 display the best OER electrochemical properties. , However, the high price, low abundance, and worse chemical stability of precious metals restrict their large-scale commercial use. , In recent years, those non-noble metal-based catalysts for electrolytic water decomposition with eminent electrochemical activity and stability have captured much more attention and can perfectly replace noble metal catalysts. , …”