Assessing the Electrocatalytic Properties of the {Cp*Rh^III}²⁺‐Polyoxometalate Derivative [H₂PW₁₁O₃₉{Rh^IIICp*(OH₂)}]^3– towards CO₂ Reduction

Abstract

Storage of electricity produced intermittently by renewable energy sources is a societal issue. Besides the use of batteries and supercapacitors, conversion of excess electricity into chemical energy is also actively investigated. The conversion of CO 2 to fuel or fuel precursors is an option that requires the use of a catalyst to overcome the high activation energy barrier. Of molecular catalysts, metal complexes with polypyridyl ligands are well represented, among which the [Cp*Rh(bpy)Cl] + and [M(bpy)(CO) 3 X] (M = Re, Mn) complexes. As redox non-innocent ligand, the bipyridine ligand is generally [a]

Polyoxometalate-Based Catalysts for CO2 Conversion

“…Inspired by organometallic CO 2 reduction catalyst [Cp*Rh III (bpy)Cl] + (Cp* = pentamethyl-cyclopentadienyl anion; bpy = 2,2′-bipyridine), [α-H 2 PW 11 O 39 {Rh III Cp*(OH 2 )}] 3− with analogous coordination structure via grafting a {Cp*Rh III } 2+ fragment on the monovacant [PW 11 O 39 ] 7− anion was prepared (Figure 12) and tested as the electrocatalyst for CO 2 reduction [54]. Compared to previously reported [CoSiW 11 O 39 ] 6− catalyst, its electrochemical behavior in the presence of CO 2 exhibited a clear improvement, strongly suggesting some interaction with the POM derivative despite the presence of a coordinating solvent.…”

“…Color code: WO 6 octahedron, navy blue; PO 4 tetrahedron, green; O, red ball. Reprinted with permission from [54]. Copyright © 2019 Wiley-VCH Verlag GmbH and Co. KGaA.…”

Molecular Transition Metal Oxide Electrocatalysts for the Reversible Carbon Dioxide–Carbon Monoxide Transformation

“…In the past, polyoxometalates substituted with transition metals have been used on occasion for the reduction of CO 2 with limited results, [7] but the majority of the reports note the use of polyoxometalates as electron/proton shuttles where the site for CO 2 reduction resides at the metal center of a coordination compound [8] . Nature's fully evolved CODH enzymes all have multi‐metal reaction sites, while the vast majority of molecular electrocatalysts are limited to single‐site transition metal compounds [3, 7a,b] . Here we present a novel, modular catalyst framework which involves the use of tri‐metallo‐substituted polyoxometalates allowing a myriad of possibilities to direct catalytic activity and selectivity, simply by choice of the active metal(s).…”

A new polypyridyl‐based Ru (II) complex as a highly efficient electrocatalyst for CO2 reduction

“…These methods are useful for recycling carbon, and provide a carbon‐neutral fuel cycle, in which the CO 2 released by combustion of fossil fuels is converted back to fuels. Among the different strategies, the electrochemical conversion of CO 2 into higher‐energy fuels and/or chemicals, such as methanol, formic acid and carbon monoxide (CO), using renewable electricity, is a worthwhile and promising approach to providing a green fuel and simultaneously moderating global warming . Despite remarkable achievements, the electrochemical reduction of CO 2 usually suffers from high overpotential and insufficient Faradaic efficiency, because CO 2 is a thermodynamically and kinetically stable molecule.…”

“…Numerous homogeneous and heterogeneous electrocatalysts have been widely used to improve the efficiency of electrochemical CO 2 reduction . Among them, transition metal complexes have attracted considerable attention owing to the accessibility of multiple oxidation states related to both metal and ligands, resulting in more positive potentials for CO 2 reduction .…”