Recent Advances in Porphyrin-Based Systems for Electrochemical Oxygen Evolution Reaction

Abstract

Oxygen evolution reaction (OER) plays a pivotal role in the development of renewable energy methods, such as water-splitting devices and the use of Zn–air batteries. First-row transition metal complexes are promising catalyst candidates due to their excellent electrocatalytic performance, rich abundance, and cheap price. Metalloporphyrins are a class of representative high-efficiency complex catalysts owing to their structural and functional characteristics. However, OER based on porphyrin systems previously have been paid little attention in comparison to the well-described oxygen reduction reaction (ORR), hydrogen evolution reaction, and CO2 reduction reaction. Recently, porphyrin-based systems, including both small molecules and porous polymers for electrochemical OER, are emerging. Accordingly, this review summarizes the recent advances of porphyrin-based systems for electrochemical OER. Firstly, the electrochemical OER for water oxidation is discussed, which shows various methodologies to achieve catalysis from homogeneous to heterogeneous processes. Subsequently, the porphyrin-based catalytic systems for bifunctional oxygen electrocatalysis including both OER and ORR are demonstrated. Finally, the future development of porphyrin-based catalytic systems for electrochemical OER is briefly prospected.

The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins

“…It is expected that the OER’s catalysis was more adequately achieved for the Co-porphyrin in a strong acidic medium because the four hydroxyl functional groups grafted on the porphyrin ring increase their tendency to form hydrogen bonds due to the substitution in the meta position. In a recent paper, it was noticed that the enhanced catalytic activity was due to the Co-porphyrin–OH intermediate [ 24 ].…”

“…Another possible explanation is the electronic effect of the substituents on the electronic structure at the cobalt centre [ 24 ]. Due to the already-known electron attractive property of OH groups in the meta position of the meso -phenyls [ 70 ] and to the surrounding hydrogen bonds, the electron densities on the Co ions decreased, and thus the nucleophilic attack of a water molecule was facilitated [ 19 ].…”

“…An example regarding the study of metalated porphyrins as OER catalysts is the one reported by Naruta et al [ 23 ], who used manganese porphyrin dimers. While in the early research macromolecules were mostly employed as homogeneous activators, their use as heterogeneous catalysts has gained ground [ 24 ], and in light of promising experimental data they have been extensively investigated as water-splitting catalysts. The progress made in the past decade concerns the identification and detailed understanding of the critical factors responsible for the water-electrocatalytic properties of the porphyrin complexes [ 19 ].…”

Recent Advances in the Photoreactions Triggered by Porphyrin-Based Triplet–Triplet Annihilation Upconversion Systems: Molecular Innovations and Nanoarchitectonics

“…Aside from photocatalytic HER, TTA-UC has also been tested for the enhancement of the photocatalytic performance of a more complicated and challenging oxygen evolution reaction (OER) [ 129 ], since it requires a theoretically high potential (1.23 V) and contains four electron transfer processes [ 130 ]. Given that triplet species are easily quenched by molecular oxygen, as depicted in Figure 11 , the sensitizer PtOEP and emitter DPA together with a cetyltrimethylammonium bromide surfactant were intercalated in a layered clay compound (saponite).…”

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.…”