Ultrasmall Abundant Metal-Based Clusters as Oxygen-Evolving Catalysts

Abstract

The oxygen evolution reaction is a crucial step in water electrolysis to develop clean and renewable energy. Although noble metalbased catalysts have demonstrated high activity for the oxygen evolution reaction, their application is limited by their high cost and low availability.Here we report the use of a molecule-to-cluster strategy for preparing ultrasmall trimetallic clusters by using the polyoxometalate molecule as a precursor. Ultrafine (0.8 nm) transition-metal clusters with controllable chemical composition are obtained. The transition-metal clusters enable highly efficient oxygen evolution through water electrolysis in alkaline media, manifested by an overpotential of 192 mV at 10 mA cm −2 , a low Tafel slope of 36 mV dec −1 , and long-term stability for 30 h of electrolysis. We note, however, that besides the excellent performance as an oxygen evolution catalyst, our molecule-to-cluster strategy provides a means to achieve well-defined transition-metal clusters in the subnanometer regime, which potentially can have an impact on several other applications.

Multiatom Catalysts for Energy‐Related Electrocatalysis

“…Tan and co‐workers developed a molecule‐to‐cluster strategy for preparing ultrafine trimetallic CoFeW clusters with well‐controlled Fe content ( Figure a). [ 136 ] Proper Fe was in situ doped into the polyoxometalate precursor, which underwent self‐assembly with ethylenediamine‐grafted C 60 to form a hybrid composite. Thermal annealing was then applied to convert the composite to MACs with well‐controlled chemical composition.…”

“…Reproduced with permission. [ 136 ] Copyright 2019, ACS. d) FT‐EXAFS spectra of Co K‐edge without phase correction for as‐prepared Co–N–C and the catalyst after activation as well as under OER for various durations.…”

Two‐Dimensional Porous Molybdenum Phosphide/Nitride Heterojunction Nanosheets for pH‐Universal Hydrogen Evolution Reaction

“…[50] Thes mall sizes of MoP and Mo 2 N particles is relative with the use of PMo 12 cluster as Mo source. [41] At hin carbon layer derived from MA can be observed (Figure 2e), which can stabilize the catalyst and increase conductivity to promote electron transfer for effective catalysis. [51] TheS TEM images and the corresponding elemental mappings reveal the uniform distribution of Mo,P , and Ne lements throughout the nanosheets (Figure 2f (Figure 2g).…”

“…[38,39] TheK eggin-structured [PMo 12 O 40 ] 3À (PMo 12 )i sp romising precursor for the synthesis of smallsized Mo-based TMICs. [40,41] It can coordinate with organic molecules containing amino groups owing to its high negative charge. [42] Melamine (MA), bearing three amine groups,i s ap otential ligand to combine with polyoxometalates (POMs).…”

Gold‐Supported Gadolinium Doped CoB Amorphous Sheet: A New Benchmark Electrocatalyst for Water Oxidation with High Turnover Frequency

“…These composite material provides bidentate sites for the reaction intermediate and increase the kinetics of electrochemical process. [ 16 ] Apart from the support, several other possible approaches to enhance the electrocatalytic performance and make water‐splitting process viable for hydrogen production have been developed including i) nano structuring to increase the selective exposure and activity of active sites, [ 22 ] ii) strong interaction of Au substrate with the transition metal that are more stable in strong electrolyte at high potential, [ 17 ] iii) introduction of some rare earth metal having empty 4f orbital that promote the electronic conduction of electrocatalyst, [ 23 ] iv) controlled morphology of electrocatalyst with high surface roughness to facilitate the movement of charges species with optimum hydrophilicity and suppress the agglomeration of active sites due to sintering or Ostwald ripening process, [ 24 ] v) self‐supported catalyst with inherently strong contact of catalyst‐support to facilitate the kinetics of overall reaction in term of low charge transfer resistance and electronic mobility. [ 10 ] Nevertheless, it remains very challenging to develop a single cost‐effective and scalable catalyst by considering the advantage of all these strategies.…”