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Abstract Single‐atom catalysts (SACs) have been attracting extensive interest in the electrocatalytic production of hydrogen peroxide by oxygen reduction reaction (ORR). This is due to the maximal efficiency of atom utilization and intimate interaction of the metal centers with the supporting matrix that may be exploited for deliberate manipulation of the electrocatalytic activity and selectivity, in comparison with the conventional nanoparticle counterparts. Herein, we summarize recent progress of the design and engineering of SACs towards ORR for H2O2generation, based on both noble and non‐noble metals. We conclude the review with a perspective highlighting the promises and challenges involved in future research.
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Dual‐Atom Catalysts for Electrochemical Energy Technologies
Rational design and engineering of high‐performance, low‐cost electrocatalysts represents a critical first step in the development of sustainable energy technologies. While single‐atom catalysts (SACs) have emerged as viable candidates, recent research has shown that the structure and activity can be further manipulated and enhanced by the incorporation of a second metal center in the close proximity, forming a binuclear configuration. Such dual‐atom catalysts (DACs) are recognized as feasible choices to break the limitations of SACs due to the synergetic effects between the bimetallic atoms and their special structures. Herein, the recent advances of DAC electrocatalysis for a range of important reactions, focusing on their synthesis, characterization, and performance, are summarized. The review is concluded with a perspective highlighting the challenges and future research directions.
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- PAR ID:
- 10397603
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Energy Technology
- Volume:
- 11
- Issue:
- 4
- ISSN:
- 2194-4288
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Electrochemical reduction reaction of CO2(CO2RR) is a promising technology for alleviating the global warming caused by the emission of CO2. This technology, however, is still in the stage of finding efficient catalysts. The catalysts must be able to convert CO2to other carbon‐based products with high activity and selectivity to valuable chemicals. In this review, previous development of heteroatom‐doped metal‐free carbon materials (H‐CMs) is briefly summarized. Recent progress of CO2RR promoted by metal single‐atom catalysts (M‐SACs) is then discussed with emphasis on the synthesis of M‐SACs, the catalytic performance, and reaction mechanisms. The high temperature pyrolysis method and electrodeposition are attracting attentions recently to prepare M‐SACs with high metal loading on N‐doped carbon materials, a very active M‐SACs system for the CO2RR. Theoretical calculations of free energy change on active sites, the Operando X‐ray absorption near edge structure (XANES), and Bader charge analysis reveal a significant role of metal oxidation state and charge transfer between metal atoms and absorbed CO. The challenges and perspectives for the extensive applications of M‐SACs in CO2RR are also discussed in this review.more » « less
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Abstract The drive for atom efficient catalysts with carefully controlled properties has motivated the development of single atom catalysts (SACs), aided by a variety of synthetic methods, characterization techniques, and computational modeling. The distinct capabilities of SACs for oxidation, hydrogenation, and electrocatalytic reactions have led to the optimization of activity and selectivity through composition variation. However, characterization methods such as infrared and X‐ray spectroscopy are incapable of direct observations at atomic scale. Advances in transmission electron microscopy (TEM) including aberration correction, monochromators, environmental TEM, and micro‐electro‐mechanical system based in situ holders have improved catalysis study, allowing researchers to peer into regimes previously unavailable, observing critical structural and chemical information at atomic scale. This review presents recent development and applications of TEM techniques to garner information about the location, bonding characteristics, homogeneity, and stability of SACs. Aberration corrected TEM imaging routinely achieves sub‐Ångstrom resolution to reveal the atomic structure of materials. TEM spectroscopy provides complementary information about local composition, chemical bonding, electronic properties, and atomic/molecular vibration with superior spatial resolution. In situ/operando TEM directly observe the evolution of SACs under reaction conditions. This review concludes with remarks on the challenges and opportunities for further development of TEM to study SACs.more » « less
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