The roles of the first and second coordination spheres in the design of molecular catalysts for H₂production and oxidation

Abstract

This tutorial review describes the development of discrete transition metal complexes as electrocatalysts for H 2 formation and oxidation. The approach involves the study of thermodynamic properties of metal hydride intermediates and the design of ligands that incorporate proton relays. The work is inspired by structural features of the H 2 ase enzymes and should be of interest to researchers in the areas of biomimetic chemistry as well as catalyst design and hydrogen utilization.

Singly versus Doubly Reduced Nickel Porphyrins for Proton Reduction: Experimental and Theoretical Evidence for a Homolytic Hydrogen‐Evolution Reaction

“…Platinum is very efficient in catalyzing H 2 production, but the low natural abundance and high cost of this noble metal restrict its widespread utilization 9, 10. Progress has been made in identifying HER catalysts by the use of molecular complexes consisting of earth‐abundant metals, such as Fe,11, 12, 13, 14, 15 Co,9, 16, 17, 18, 19, 20 Ni,21, 22, 23, 24, 25 and Mo 26, 27. For example, Co and Fe complexes of N‐based macrocyclic ligands (e.g.…”

Molecular Chemistry for Solar Fuels: From Natural to Artificial Photosynthesis

“…[5] Several of these catalysts could in principle be used for solar fuel production, but due to the scarcity of these elements they are not sustainable or suitable for development on larger scale. Abundant elements for active electron acceptor catalysts are Co, Ni, and Fe [17,22,52] that constitute the active parts in several well functioning systems. It is more difficult to accomplish light driven water oxidation, and only a few systems have been shown to work.…”

“…The catalysts may contain abundant materials like Co, Fe, Mn, or Ni. [7,10,[21][22][23] It is not unlikely that these mixed systems will be the winning concept since they combine advantages from both types of systems.…”

Synthesis and reactivity of cyclopentadienyl ruthenium complexes containing ferrocenylselenolates

“…In recent years, considerable attention has been focused on transition metal complexes with chalcogen ligands as synthetic models for the active sites of several metalloenzymes and heterogeneous sulfide catalysts [1][2][3][4]. In this context, ligands based on the ferrocene backbone are of great interest in cluster, materials, and inorganic synthesis due to the natural redox active behavior of the iron centers of the ferrocenyl moiety [5,6].…”