Electronic Design Criteria for O−O Bond Formation via Metal−Oxo Complexes

Betley, Theodore A.; Wu, Qin; Voorhis, Troy Van; Nocera, Daniel G.

doi:10.1021/ic701972n

Cited by 399 publications

(371 citation statements)

References 101 publications

(168 reference statements)

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“…7a). It is sometimes referred to as an acid-base mechanism 96,97 because it proceeds through a series of acid-base steps, in which OH, an oxygen nucleophile (Lewis acid) attacks a metal-bound, electrophilic oxygen surface species (Lewis base). An identical reaction mechanism was proposed by Goodenough et al for the ORR on pyrochlore and rutile oxides (Fig.…”

Section: Proposed Reaction Mechanisms On Oxide Surfacesmentioning

confidence: 99%

Toward the rational design of non-precious transition metal oxides for oxygen electrocatalysis

Hong

Risch

Stoerzinger

et al. 2015

Energy Environ. Sci.

1,767

1,491

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REVIEWThis journal is © The Royal Society of Chemistry 2013 J. Name., 2013, 00, 1-3 | 1 In this Review, we discuss the state-of-the-art understanding of non-precious transition metal oxides that catalyze the oxygen reduction and evolution reactions. Understanding and mastering the kinetics of oxygen electrocatalysis is instrumental to making use of photosynthesis, advancing solar fuels, fuel cells, electrolyzers, and metal-air batteries. We first present key insights, assumptions and limitations of well-known activity descriptors and reaction mechanisms in the past four decades. The turnover frequency of crystalline oxides as promising catalysts is also put into perspective with amorphous oxides and photosystem II. Particular attention is paid to electronic structure parameters that can potentially govern the adsorbate binding strength and thus provide simple rationales and design principles to predict new catalyst chemistries with enhanced activity. We share new perspective synthesizing mechanism and electronic descriptors developed from both molecular orbital and solid state band structure principles. We conclude with an outlook on the opportunities in future research within this rapidly developing field. Broader ContextThe formation of chemical bonds is an energy dense mode of storing energy. In both nature and technology, the electrochemical generation and consumption of fuels is one of the most efficient routes for energy usage. Solar and electrical energy can be stored in chemical bonds by splitting water or metal oxides to produce hydrogen and metal. These compounds can then be oxidized to produce energy when coupled to the reduction of oxygen. However, these device efficiencies are severely limited by the catalysis of oxygen electrochemical processes -namely the oxygen reduction reaction and oxygen evolution reaction, which have slow kinetics. Non-precious transition metal oxides show promise as cost-effective substitutes for noble metals in commercially viable renewable energy storage and conversion devices. Furthermore, this class of materials has ben efitted from a wealth of spectroscopic and first-principles studies in the past few decades, providing the frameworks and theories needed to understand the electronic structure and design optimal catalysts. The incredibly diverse range of chemistries and physical properties that can be explored in oxide families afford numerous degrees of freedom for conducting systematic investigations relating intrinsic mat erial properties to catalytic performance. Here, we present background on the fundamental concepts in catalysis for the rational design of transition metal perovskite oxide catalysts for oxygen electrocatalysis and critically examine the current understanding a nd its impact on future directions of perovskite catalysts.

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Section: Proposed Reaction Mechanisms On Oxide Surfacesmentioning

confidence: 99%

Toward the rational design of non-precious transition metal oxides for oxygen electrocatalysis

Hong

Risch

Stoerzinger

et al. 2015

Energy Environ. Sci.

1,767

1,491

View full text Add to dashboard Cite

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“…One factor distinguishing molecular catalysts from solid catalysts is that, aside from their homogeneous nature, the electrochemically formed high‐valence metal–oxo species can form an O−O bond by either an acid–base reaction with water or via the direct coupling of two neighboring oxo species 2, 6, 7. In contrast, for heterogeneous catalysts, the OER is believed to proceed via four consecutive proton‐coupled electron transfer (PCET) steps, with the metallic center serving as active site (Supporting Information, Figure S1) 8.…”

mentioning

confidence: 99%

Chemical Recognition of Active Oxygen Species on the Surface of Oxygen Evolution Reaction Electrocatalysts

et al. 2017

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Owing to the transient nature of the intermediates formed during the oxygen evolution reaction (OER) on the surface of transition metal oxides, their nature remains largely elusive by the means of simple techniques. The use of chemical probes is proposed, which, owing to their specific affinities towards different oxygen species, unravel the role played by these species on the OER mechanism. For that, tetraalkylammonium (TAA) cations, previously known for their surfactant properties, are introduced, which interact with the active oxygen sites and modify the hydrogen bond network on the surface of OER catalysts. Combining chemical probes with isotopic and pH‐dependent measurements, it is further demonstrated that the introduction of iron into amorphous Ni oxyhydroxide films used as model catalysts deeply modifies the proton exchange properties, and therefore the OER mechanism and activity.

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“…Crucial in the above configuration is the separation of the functions of light collection and conversion from catalysis. Whereas light collection/conversion generates electron/ hole pairs one at a time, water splitting is a four-electron/hole process (2,3). Hence, the multielectron catalysts of PSII and PSI, positioned at the terminus of the photosynthetic charge-separating network, are compulsory so that the one photon-one-electron/ hole "wireless current" can be bridged to the four-electron/hole chemistry of water splitting.…”

mentioning

confidence: 99%

Light-induced water oxidation at silicon electrodes functionalized with a cobalt oxygen-evolving catalyst

Pijpers

Winkler

Surendranath³

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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199

194

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Integrating a silicon solar cell with a recently developed cobaltbased water-splitting catalyst (Co-Pi) yields a robust, monolithic, photo-assisted anode for the solar fuels process of water splitting to O 2 at neutral pH. Deposition of the Co-Pi catalyst on the Indium Tin Oxide (ITO)-passivated p-side of a np-Si junction enables the majority of the voltage generated by the solar cell to be utilized for driving the water-splitting reaction. Operation under neutral pH conditions fosters enhanced stability of the anode as compared to operation under alkaline conditions (pH 14) for which long-term stability is much more problematic. This demonstration of a simple, robust construct for photo-assisted water splitting is an important step towards the development of inexpensive direct solar-to-fuel energy conversion technologies.photoelectrochemical | hydrogen | solar energy | storage P hotosynthetic organisms convert the energy of sunlight into chemical energy by splitting water, producing molecular oxygen and hydrogen equivalents in the highly conserved enzyme complex photosystem II (PSII) (1). Absorbed photons are transferred to the reaction center of PSII, where a single electron/hole charge separation occurs. The oxidative power of the photo-produced hole in PSII is transferred to the oxygen evolving complex (OEC) where water splitting occurs. The electron is transferred to the adjacent photosystem I (PSI), where it participates in the reduction reaction of NAD þ into NADH, which is ultimately used to fix CO 2 . Crucial in the above configuration is the separation of the functions of light collection and conversion from catalysis. Whereas light collection/conversion generates electron/ hole pairs one at a time, water splitting is a four-electron/hole process (2, 3). Hence, the multielectron catalysts of PSII and PSI, positioned at the terminus of the photosynthetic charge-separating network, are compulsory so that the one photon-one-electron/ hole "wireless current" can be bridged to the four-electron/hole chemistry of water splitting.An artificial photosynthesis can be designed if the one-electron/hole wireless current of a semiconductor can be integrated directly with catalysts to perform the four-electron-four proton catalysis of water splitting. To this end, an important recent advance has been the creation of a cobalt-phosphate (Co-Pi) catalyst (4, 5) that captures the functional elements of the OEC of PSII (6). As in PSII OEC, the Co-Pi catalyst self-assembles upon oxidation of an earth-abundant metal [Co 2þ for Co-Pi vs. Mn 2þ for OEC (7-9)] in phosphate-buffered solutions at neutral pH (4, 10), exhibits high activity in natural water and sea water at room temperature (11), activates water by proton-coupled electron transfer (3) [as does the OEC of PSII (12, 13)], and is self-healing (14) [as is PSII (15-18)]. Moreover, X-ray Absorption Spectroscopy (XAS) studies (19,20) have established that the Co-Pi catalyst is a structural relative of PSII OEC. PSII OEC is a Mn 3 CaO 4 -Mn cubane (21) where the fourth M...

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Electronic Design Criteria for O−O Bond Formation via Metal−Oxo Complexes

Cited by 399 publications

References 101 publications

Toward the rational design of non-precious transition metal oxides for oxygen electrocatalysis

Toward the rational design of non-precious transition metal oxides for oxygen electrocatalysis

Chemical Recognition of Active Oxygen Species on the Surface of Oxygen Evolution Reaction Electrocatalysts

Light-induced water oxidation at silicon electrodes functionalized with a cobalt oxygen-evolving catalyst

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