Iron Phthalocyanine/Graphene Composites as Promising Electrocatalysts for the Oxygen Reduction Reaction

Abstract

Recently, the development of non-precious electrocatalysts for the oxygen reduction reaction (ORR) has become important in replacing currently employed platinum (Pt)-based catalysts. Although Pt-based catalysts exhibit satisfactory ORR performances, their high price, easy methanol/CO2 poisoning, and poor long-term stability significantly hamper the forward movement of fuel cell technology. Among the various candidates, graphene-supported iron phthalocyanine (FePc) composites have attracted great attention because of their unique advantages, including low cost, good dimensional stability, high durability, and tunable catalytic activity. In the composite catalyst, FePc molecules are immobilized on graphene via noncovalent or covalent interactions. In addition, two-dimensional graphene substrates can improve not only the electrical conductivity of the composite, but also the dispersion of FePc molecules, triggering a significant improvement in the catalytic properties of the composite catalyst. Herein, we summarize the recent advances in FePc/graphene composite catalysts used for the ORR. Moreover, we discuss the challenges and future perspectives of this promising field.

Regulating Electronic Descriptors for the Enhanced ORR Activity of FePc-Functionalized Graphene via Substrate Doping and/or Ligand Exchange: A Theoretical Study

“…Note that boron- and nitrogen-doped graphene structures can be experimentally prepared using many methods, such as liquid process, thermal annealing, and CVD, to maintain atomic doping percent between 0.3 and 16.7 atom % for N-doping and 0.5 and 13.85 atom % for B-doping. ,, It is also to be noted that monolayer metal phthalocyanines can be grown on doped graphene surfaces . It has been shown experimentally that various graphene iron phthalocyanine composite catalysts displayed better long-term stability and showed higher tolerance to methanol crossover compared to Pt/C in alkaline media. − …”

2,6-Diaminopyridine-Based Polyurea as an ORR Electrocatalyst of an Anion Exchange Membrane Fuel Cell

“…Another option is to use a macrocyclic compound [ 10 , 11 , 12 , 13 , 14 , 15 ] to capture metal ions by nitrogen, i.e., N MOFs. Two major N-macrocyclic compounds used to prepare MOFs and M–Nx–Cs are porphyrin [ 16 , 17 , 18 , 19 , 20 , 21 ] and phthalocyanine [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Both use four -Ns to complex with the central metal and can create an M–N4–C structure after calcination.…”

Tetraphenolphthalein Cobalt(II) Phthalocyanine Polymer Modified with Multiwalled Carbon Nanotubes as an Efficient Catalyst for the Oxygen Reduction Reaction

“…The efficiency of the electrocatalytic reduction of O 2 depends on the metal center and substituents attached to the Pc ring. 11 − 13 The characteristic properties of the Pc s can be modulated by attaching various functional groups. Among different substituents, lactone rings provide an extended conjugation and improve the conductivity and redox activity, leading to high catalytic activity.…”

“…These organic molecules are extensively used for potential applications in nonlinear optics, supramolecular chemistry, electrocatalysis, energy storage, charge transfer process, data storage devices, and so forth. − The Pc s have been studied as efficient ORR catalysts to replace expensive Pt/C catalysts. The efficiency of the electrocatalytic reduction of O 2 depends on the metal center and substituents attached to the Pc ring. − The characteristic properties of the Pc s can be modulated by attaching various functional groups. Among different substituents, lactone rings provide an extended conjugation and improve the conductivity and redox activity, leading to high catalytic activity.…”