Longitudinally Grafting of Graphene with Iron Phthalocyanine‐based Porous Organic Polymer to Boost Oxygen Electroreduction

Abstract

Iron phthalocyanine‐based polymers (PFePc) are attractive noble‐metal‐free candidates for catalyzing oxygen reduction reaction (ORR). However, the low site‐exposure degree and poor electrical conductivity of bulk PFePc restricted their practical applications. Herein, laminar PFePc nanosheets covalently and longitudinally linked to graphene (3D‐G‐PFePc) was prepared. Such structural engineering qualifies 3D‐G‐PFePc with high site utilization and rapid mass transfer. Thence, 3D‐G‐PFePc demonstrates efficient ORR performance with a high specific activity of 69.31 μA cm−2, a high mass activity of 81.88 A g−1, and a high turnover frequency of 0.93 e s−1 site−1 at 0.90 V vs. reversible hydrogen electrode in O2‐saturated 0.1 M KOH, outperforming the lamellar PFePc wrapped graphene counterpart. Systematic electrochemical analyses integrating variable‐frequency square wave voltammetry and in situ scanning electrochemical microscopy further underline the rapid kinetics of 3D‐G‐PFePc towards ORR.

Well‐defined N3C1‐anchored Single‐Metal‐Sites for Oxygen Reduction Reaction

“…Moreover, NCPor‐Co exhibits a high limiting current density ( J L ) of 5.35 mA cm −2 , which is higher than that of Por‐Co ( J L =5.22 mA cm −2 ). However, NCPor‐Co shows a higher Tafel slope (104 mV dec −1 ) than do commercial Pt/C (99 mV dec −1 ) and Por‐Co (68 mV dec −1 ), which reveals that NCPor‐Co has slower kinetics in the ORR than does Por‐Co (Figure S42) [33] . To investigate the kinetic parameters of NCPor‐Co and Por‐Co, LSV was performed at different rotation rates from 225 to 1600 rpm.…”

“…However, NCPor-Co shows a higher Tafel slope (104 mV dec À 1 ) than do commercial Pt/C (99 mV dec À 1 ) and Por-Co (68 mV dec À 1 ), which reveals that NCPor-Co has slower kinetics in the ORR than does Por-Co (Figure S42). [33] To investigate the kinetic parameters of NCPor-Co and Por-Co, LSV was performed at different rotation rates from 225 to 1600 rpm. The Koutecky-Levich plots of NCPor-Co exhibit a linear relationship, which indicates that NCPor-Co follows O 2 concentration related first-order reaction kinetics and shows high selectivity for four-electron transfer process (Figure 2b).…”

Engineering organic polymers as emerging sustainable materials for powerful electrocatalysts

“…13b). 213 The as-synthesized 3D-G-PFePc exhibits efficient catalytic performance for the ORR with a half-wave potential of 0.93 V and high mass activity due to the hierarchical architecture and enhanced conductivity. In addition, Mousavi et al introduced a controllable electrodeposition technique that enables in situ growth of a trimetallic Fe–Co–Ni MOF on Ni foam, realized through a unique Fe–Co–Ni trilayer architecture.…”

Advanced Architectures of Air Electrodes in Zinc–Air Batteries and Hydrogen Fuel Cells

“…In recent years, with the rapid development of stable aqueous Zn electrodes and high-efficiency oxygen electrocatalysts, aqueous ZABs are attracting more and more attention in decarbonized energy storage. [41][42][43][44][45][46] Due to the high safety and secondary cycle characteristics, ZAB stands out from all metal-air batteries. Despite the early use of ZABs in mechanically recharged form, the additional cost of supplying Zn anodes has led to its lack of widespread adoption.…”