Water‐Soluble Polymers with Appending Porphyrins as Bioinspired Catalysts for the Hydrogen Evolution Reaction

Abstract

Molecular design to improve catalyst performance is significant but challenging. In enzymes, residue groups that are close to reaction centers play critical roles in regulating activities. Using this bioinspired strategy, three water‐soluble polymers were designed with appending Co porphyrins and different side‐chain groups to mimic enzyme reaction centers and activity‐controlling residue groups, respectively. With these polymers, high hydrogen evolution efficiency was achieved in neutral aqueous media for electro‐ (turnover frequency >2.3×104 s−1) and photocatalysis (turnover number >2.7×104). Porphyrin units are surrounded and protected by polymer chains, and more importantly, the activity can be tuned with different side‐chain groups. Therefore, instead of revising molecular structures that is difficult from both design and synthesis points of view, polymers can be used to improve molecular solubility and stability and simultaneously regulate activity by using side‐chain groups.

Supramolecular Modulation of Molecular Conformation of Metal Porphyrins toward Remarkably Enhanced Multipurpose Electrocatalysis and Ultrahigh‐Performance Zinc–Air Batteries

“…On the one hand, combining metal porphyrins with highly conductive supports such as graphene [19][20][21] and carbon nanotubes [22,23] have been demonstrated to promote charge transfer efficiently. On the other hand, effective strategies to enhance the electrocatalytic activity of metal porphyrins have been focused on adjusting the coordination environment around the active site by expanding/modifying the molecular structure of metal porphyrins such as axial coordination, [24,25] constructing crystalline porous materials [26][27][28] and introducing functional groups, [29,30] Modulating the intrinsic catalytic activity of molecular catalysts to improve electrocatalytic performance is significant but challenging. Herein, a simple yet effective strategy to induce molecular flattening of Co (III) meso-tetra (N-methyl-4-pyridyl) porphyrine (Co-TMPyP) by supramolecular assembly with chemically converted graphene (CCG) via synergistic electrostatic and π-π interactions is reported.…”

Hydrogen evolution catalysis by terminal molybdenum-oxo complexes

“…The non-sustainability of platinum, by far the best catalyst for reduction of protons to hydrogen (the hydrogen evolution reaction [HER]), and also inspiration from biology (e.g., Fe-hydrogenases) continues to drive focus on developing catalysts based on cheap, non-toxic, and earth-abundant metal complexes ( Abbas and Bang, 2015 ; Bullock et al., 2014 ; Fukuzumi et al., 2018 ; Guo et al., 2020 ; Mondal et al., 2013 ; Roger et al., 2017 ; Xie et al., 2020 ). Molybdenum may safely be considered the only non-precious heavy transition metal, and it is also essential for human life due to its presence and roles in more than 30 enzymes (e.g., DMSO reductase, sulfite oxidase, xanthine oxidase) ( Schwarz et al., 2009 ).…”

Metal–Organic‐Framework‐Supported Molecular Electrocatalysis for the Oxygen Reduction Reaction

“…Molecular electrocatalysis has gained increasing interests because catalyst structures are clear and can be systematically modified. [1][2][3][4][5][6][7][8][9][10] These features are critical for studying reaction mechanisms and structure-function relationships, which are of fundamental significance for catalyst design. [11][12][13][14][15][16][17][18] Despite these benefits, however, the practical use of molecular electrocatalysis requires immobilization of catalysts on proper supports considering that (1) only those molecules close to electrodes can be activated for reactions with substrates and (2) immobilized catalysts are preferred for reusing and for integrating to electrochemical devices.…”