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1.
Adv Mater ; : e2401454, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685794

RESUMO

Single atom catalysts (SACs) are atomic-level-engineered materials with high intrinsic activity. Catalytic centers of SACs are typically the transition metal (TM)-nonmetal coordination sites, while the functions of coexisting non-TM-bonded functionalities are usually overlooked in catalysis. Herein, the scalable preparation of carbon-supported cobalt-anchored SACs (CoCN) with controlled Co─N sites and free functional N species is reported. The role of metal- and nonmetal-bonded functionalities in the SACs for peroxymonosulfate (PMS)-driven Fenton-like reactions is first systematically studied, revealing their contribution to performance improvement and pathway steering. Experiments and computations demonstrate that the Co─N3C coordination plays a vital role in the formation of a surface-confined PMS* complex to trigger the electron transfer pathway and promote kinetics because of the optimized electronic state of Co centers, while the nonmetal-coordinated graphitic N sites act as preferable pollutant adsorption sites and additional PMS activation sites to accelerate electron transfer. Synergistically, CoCN exhibits ultrahigh activity in PMS activation for p-hydroxybenzoic acid oxidation, achieving complete degradation within 10 min with an ultrahigh turnover frequency of 0.38 min-1, surpassing most reported materials. These findings offer new insights into the versatile functions of N species in SACs and inspire rational design of high-performance catalysts in complicated heterogeneous systems.

2.
Chem Soc Rev ; 53(4): 2022-2055, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38204405

RESUMO

Beyond conventional electrocatalyst engineering, recent studies have unveiled the effectiveness of manipulating the local reaction environment in enhancing the performance of electrocatalytic reactions. The general principles and strategies of local environmental engineering for different electrocatalytic processes have been extensively investigated. This review provides a critical appraisal of the recent advancements in local reaction environment engineering, aiming to comprehensively assess this emerging field. It presents the interactions among surface structure, ions distribution and local electric field in relation to the local reaction environment. Useful protocols such as the interfacial reactant concentration, mass transport rate, adsorption/desorption behaviors, and binding energy are in-depth discussed toward modifying the local reaction environment. Meanwhile, electrode physical structures and reaction cell configurations are viable optimization methods in engineering local reaction environments. In combination with operando investigation techniques, we conclude that rational modifications of the local reaction environment can significantly enhance various electrocatalytic processes by optimizing the thermodynamic and kinetic properties of the reaction interface. We also outline future research directions to attain a comprehensive understanding and effective modulation of the local reaction environment.

3.
Chem Soc Rev ; 53(3): 1552-1591, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38168798

RESUMO

Urea is one of the most essential reactive nitrogen species in the nitrogen cycle and plays an indispensable role in the water-energy-food nexus. However, untreated urea or urine wastewater causes severe environmental pollution and threatens human health. Electrocatalytic and photo(electro)catalytic urea oxidation technologies under mild conditions have become promising methods for energy recovery and environmental remediation. An in-depth understanding of the reaction mechanisms of the urea oxidation reaction (UOR) is important to design efficient electrocatalysts/photo(electro)catalysts for these technologies. This review provides a critical appraisal of the recent advances in the UOR by means of both electrocatalysis and photo(electro)catalysis, aiming to comprehensively assess this emerging field from fundamentals and materials, to practical applications. The emphasis of this review is on the design and development strategies for electrocatalysts/photo(electro)catalysts based on reaction pathways. Meanwhile, the UOR in natural urine is discussed, focusing on the influence of impurity ions. A particular emphasis is placed on the application of the UOR in energy and environmental fields, such as hydrogen production by urea electrolysis, urea fuel cells, and urea/urine wastewater remediation. Finally, future directions, prospects, and remaining challenges are discussed for this emerging research field. This critical review significantly increases the understanding of current progress in urea conversion and the development of a sustainable nitrogen economy.

4.
Adv Mater ; 36(14): e2307913, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37756435

RESUMO

Hydrogenation reactions play a critical role in the synthesis of value-added products within the chemical industry. Electrocatalytic hydrogenation (ECH) using water as the hydrogen source has emerged as an alternative to conventional thermocatalytic processes for sustainable and decentralized chemical synthesis under mild conditions. Among the various ECH catalysts, copper-based (Cu-based) nanomaterials are promising candidates due to their earth-abundance, unique electronic structure, versatility, and high activity/selectivity. Herein, recent advances in the application of Cu-based catalysts in ECH reactions for the upgrading of valuable chemicals are systematically analyzed. The unique properties of Cu-based catalysts in ECH are initially introduced, followed by design strategies to enhance their activity and selectivity. Then, typical ECH reactions on Cu-based catalysts are presented in detail, including carbon dioxide reduction for multicarbon generation, alkyne-to-alkene conversion, selective aldehyde conversion, ammonia production from nitrogen-containing substances, and amine production from organic nitrogen compounds. In these catalysts, the role of catalyst composition and nanostructures toward different products is focused. The co-hydrogenation of two substrates (e.g., CO2 and NOx n, SO3 2-, etc.) via C─N, C─S, and C─C cross-coupling reactions are also highlighted. Finally, the critical issues and future perspectives of Cu-catalyzed ECH are proposed to accelerate the rational development of next-generation catalysts.

5.
Nat Commun ; 14(1): 5842, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37730706

RESUMO

Renewable energy-based electrocatalytic oxidation of organic nucleophiles (e.g.methanol, urea, and amine) are more thermodynamically favourable and, economically attractive to replace conventional pure water electrooxidation in electrolyser to produce hydrogen. However, it is challenging due to the competitive oxygen evolution reaction under a high current density (e.g., >300 mA cm-2), which reduces the anode electrocatalyst's activity and stability. Herein, taking lower energy cost urea electrooxidation reaction as the model reaction, we developed oxyanion-engineered Nickel catalysts to inhibit competing oxygen evolution reaction during urea oxidation reaction, achieving an ultrahigh 323.4 mA cm-2 current density at 1.65 V with 99.3 ± 0.4% selectivity of N-products. In situ spectra studies reveal that such in situ generated oxyanions not only inhibit OH- adsorption and guarantee high coverage of urea reactant on active sites to avoid oxygen evolution reaction, but also accelerate urea's C - N bond cleavage to form CNO - intermediates for facilitating urea oxidation reaction. Accordingly, a comprehensive mechanism for competitive adsorption behaviour between OH- and urea to boost urea electrooxidation and dynamic change of Ni active sites during urea oxidation reaction was proposed. This work presents a feasible route for high-efficiency urea electrooxidation reaction and even various electrooxidation reactions in practical applications.

6.
J Am Chem Soc ; 145(28): 15565-15571, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37395649

RESUMO

Ethylene oxidation to oxygenates via electrocatalysis is practically promising because of less energy input and CO2 output compared with traditional thermal catalysis. However, current ethylene electrooxidation reaction (EOR) is limited to alkaline and neutral electrolytes to produce acetaldehyde and ethylene glycol, significantly limiting cell energy efficiency. Here, we report for the first time an EOR to 2-chloroethanol product in a strongly acidic environment with natural seawater as an electrolyte. We demonstrate a 2-chloroethanol Faradaic efficiency (FE) of ∼70% with a low electrical energy consumption of ∼1.52 × 10-3 kWh g-1 over a commercial Pd catalyst. We establish a mechanism to evidence that 2-chloroethanol is produced at low potentials via direct interaction of adsorbed chloride anions (*Cl) with ethylene reactant because of the high coverage of *Cl during reaction. Importantly, this differs from the accepted multiple step mechanism of subsequent chlorine oxidation and ethylene chlorination reactions at high potentials. With highly active Cl- participation, the production rate for 2-chloroethanol in acidic seawater is a high 26.3 g m-2 h-1 at 1.6 V operation. Significantly, we show that this is 223 times greater than that for ethylene glycol generation in acidic freshwater. We demonstrate chloride-participated EOR in a proton exchange membrane electrolyzer that exhibits a 68% FE for 2-chloroethanol at 2.2 V operation in acidic seawater. This new understanding can be used for designing selective anode oxidation reactions in seawater under mild conditions.

7.
Small ; 19(45): e2303428, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37434078

RESUMO

Obtaining partial methane oxidation reaction (MOR) with various oxygenates via a mild electrochemical method is practically difficult because of activation of stable C─H bond and consequent reaction pathway regulation. Here, a real-time tandem MOR with cascaded plasma and electrocatalysis to activate and convert the methane (CH4 ) synergistically is reported for the first time. Boosted CH4 conversion is demonstrated toward value-added products including, alcohols, carboxylates, and ketone via use of commercial Pd-based electrocatalysts. Compared with hash industrial processes, a mild condition, that is, anode potential < 1.0 V versus RHE (reversible hydrogen electrode) is used that mitigates overoxidation of oxygenates and obviates competing reaction(s). One evidence that Pd(II) sites and surface adsorbed hydroxyls are important in facilitating activated-CH4 species conversion, and establish a reaction mechanism for conversion(s) that involves coupling reactions between adsorbed hydroxyls, carbon monoxide and C1 /C2 alkyls. One conclude that pre-activation is important in boosting electrochemical partial MOR under mild conditions and will be of benefit in the development of sustainable CH4 conversion technology.

8.
Angew Chem Int Ed Engl ; 62(21): e202303011, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36949029

RESUMO

Aqueous Zn-Iodine (I2 ) batteries are attractive for large-scale energy storage. However, drawbacks include, Zn dendrites, hydrogen evolution reaction (HER), corrosion and, cathode "shuttle" of polyiodines. Here we report a class of N-containing heterocyclic compounds as organic pH buffers to obviate these. We evidence that addition of pyridine /imidazole regulates electrolyte pH, and inhibits HER and anode corrosion. In addition, pyridine and imidazole preferentially absorb on Zn metal, regulating non-dendritic Zn plating /stripping, and achieving a high Coulombic efficiency of 99.6 % and long-term cycling stability of 3200 h at 2 mA cm-2 , 2 mAh cm-2 . It is also confirmed that pyridine inhibits polyiodines shuttling and boosts conversion kinetics for I- /I2 . As a result, the Zn-I2 full battery exhibits long cycle stability of >25 000 cycles and high specific capacity of 105.5 mAh g-1 at 10 A g-1 . We conclude organic pH buffer engineering is practical for dendrite-free and shuttle-free Zn-I2 batteries.

9.
J Am Chem Soc ; 144(32): 14936-14944, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35926980

RESUMO

An ampere-level current density of CO2 electrolysis is critical to realize the industrial production of multicarbon (C2+) fuels. However, under such a large current density, the poor CO intermediate (*CO) coverage on the catalyst surface induces the competitive hydrogen evolution reaction, which hinders CO2 reduction reaction (CO2RR). Herein, we report reliable ampere-level CO2-to-C2+ electrolysis by heteroatom engineering on Cu catalysts. The Cu-based compounds with heteroatom (N, P, S, O) are electrochemically reduced to heteroatom-derived Cu with significant structural reconstruction under CO2RR conditions. It is found that N-engineered Cu (N-Cu) catalyst exhibits the best CO2-to-C2+ productivity with a remarkable Faradaic efficiency of 73.7% under -1100 mA cm-2 and an energy efficiency of 37.2% under -900 mA cm-2. Particularly, it achieves a C2+ partial current density of -909 mA cm-2 at -1.15 V versus reversible hydrogen electrode, which outperforms most reported Cu-based catalysts. In situ spectroscopy indicates that heteroatom engineering adjusts *CO adsorption on Cu surface and alters the local H proton consumption in solution. Density functional theory studies confirm that the high adsorption strength of *CO on N-Cu results from the depressed HER and promoted *CO adsorption on both bridge and atop sites of Cu, which greatly reduces the energy barrier for C-C coupling.

10.
Nat Commun ; 13(1): 3754, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768462

RESUMO

Electroreduction of carbon dioxide (CO2) into multicarbon products provides possibility of large-scale chemicals production and is therefore of significant research and commercial interest. However, the production efficiency for ethanol (EtOH), a significant chemical feedstock, is impractically low because of limited selectivity, especially under high current operation. Here we report a new silver-modified copper-oxide catalyst (dCu2O/Ag2.3%) that exhibits a significant Faradaic efficiency of 40.8% and energy efficiency of 22.3% for boosted EtOH production. Importantly, it achieves CO2-to-ethanol conversion under high current operation with partial current density of 326.4 mA cm-2 at -0.87 V vs reversible hydrogen electrode to rank highly significantly amongst reported Cu-based catalysts. Based on in situ spectra studies we show that significantly boosted production results from tailored introduction of Ag to optimize the coordinated number and oxide state of surface Cu sites, in which the *CO adsorption is steered as both atop and bridge configuration to trigger asymmetric C-C coupling for stablization of EtOH intermediates.

11.
Natl Sci Rev ; 8(1): nwaa088, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34691549

RESUMO

Understanding the correlation between exposed surfaces and performances of controlled nanocatalysts can aid effective strategies to enhance electrocatalysis, but this is as yet unexplored for the nitrogen reduction reaction (NRR). Here, we first report controlled synthesis of well-defined Pt3Fe nanocrystals with tunable morphologies (nanocube, nanorod and nanowire) as ideal model electrocatalysts for investigating the NRR on different exposed facets. The detailed electrocatalytic studies reveal that the Pt3Fe nanocrystals exhibit shape-dependent NRR electrocatalysis. The optimized Pt3Fe nanowires bounded with high-index facets exhibit excellent selectivity (no N2H4 is detected), high activity with NH3 yield of 18.3 µg h-1 mg-1 cat (0.52 µg h-1 cm-2 ECSA; ECSA: electrochemical active surface area) and Faraday efficiency of 7.3% at -0.05 V versus reversible hydrogen electrode, outperforming the {200} facet-enclosed Pt3Fe nanocubes and {111} facet-enclosed Pt3Fe nanorods. They also show good stability with negligible activity change after five cycles. Density functional theory calculations reveal that, with high-indexed facet engineering, the Fe-3d band is an efficient d-d coupling correlation center for boosting the Pt 5d-electronic exchange and transfer activities towards the NRR.

12.
Adv Mater ; 33(51): e2105308, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34610648

RESUMO

To improve the electroactivity and stability of electrocatalysts, various modulation strategies have been applied in nanocatalysts. Among different methods, heteroatom doping has been considered as an effective method, which modifies the local bonding environments and the electronic structures. Meanwhile, the design of novel two-dimensional (2D) nanostructures also offers new opportunities for achieving efficient electrocatalysts. In this work, Mn-doped ultrathin Ru nanosheet branches (RuMn NSBs), a newly reported 2D nanostructure, is synthesized. With the ultrathin and naturally abundant edges, the RuMn NSBs have exhibited bifunctionalities of hydrogen evolution reaction and oxygen evolution reaction with high electroactivity and durability in different electrolytes. Experimental characterizations have revealed that RuO bonds are shortened due to Mn doping, which is the key factor that leads to improved electrochemical performances. Density functional theory (DFT) calculations have confirmed that the introduction of Mn enables flexible modulations on the valence states of Ru sites. The inversed redox state evolutions of Ru and Mn sites not only improve the electroactivity for the water splitting but also the long-term stability due to the pinning effect of Ru sites. This work has provided important inspirations for the design of future advanced Ru-based electrocatalysts with high performances and durability.

13.
Angew Chem Int Ed Engl ; 60(32): 17430-17434, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34050593

RESUMO

Over the past decades, despite the substantial efforts that have been devoted to the modifications of Pt nanoparticles (NPs) to tailor their selectivities for hydrogenation reactions, there are still a lack of facile strategies for precisely regulation of the surface properties of NPs, especially for those with small sizes. In this work, we propose a top-down thermal annealing strategy for tuning the surface properties of Pt-based NPs (≈4 nm) without the occurrence of aggregation. Compared to conventional bottom-up methods, the present top-down strategy can precisely regulate the surface compositions of Pt-Cd NPs and other ternary Pt-Cd-M NPs (M=Fe, Ni, Co, Mn, and Sn). The optimized Pt-Cd NPs exhibit excellent selectivity toward phenylacetylene and 4-nitrostyrene hydrogenations with a styrene selectivity and 4-aminophenyl styrene selectivity of 95.2 % and 94.5 %, respectively. This work provides a general strategy for the surface reconstructions of Pt-based NPs, and promotes fundamental research on catalyst design for heterogeneous catalysis.

14.
Adv Mater ; 33(50): e2004243, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33749035

RESUMO

Proton exchange membrane (PEM) water electrolyzers hold great significance for renewable energy storage and conversion. The acidic oxygen evolution reaction (OER) is one of the main roadblocks that hinder the practical application of PEM water electrolyzers. Highly active, cost-effective, and durable electrocatalysts are indispensable for lowering the high kinetic barrier of OER to achieve boosted reaction kinetics. To date, a wide spectrum of advanced electrocatalysts has been designed and synthesized for enhanced acidic OER performance, though Ir and Ru based nanostructures still represent the state-of-the-art catalysts. In this Progress Report, recent research progress in advanced electrocatalysts for improved acidic OER performance is summarized. First, fundamental understanding about acidic OER including reaction mechanisms and atomic understanding to acidic OER for rational design of efficient electrocatalysts are discussed. Thereafter, an overview of the progress in the design and synthesis of advanced acidic OER electrocatalysts is provided in terms of catalyst category, i.e., metallic nanostructures (Ir and Ru based), precious metal oxides, nonprecious metal oxides, and carbon based nanomaterials. Finally, perspectives to the future development of acidic OER are provided from the aspects of reaction mechanism investigation and more efficient electrocatalyst design.

15.
ACS Nano ; 15(1): 1039-1047, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33377388

RESUMO

The design of efficient copper-based (Cu-based) carbon dioxide reduction (CO2RR) electrocatalysts is crucial for converting CO2 to value-added liquid products. In this work, we demonstrate that the strong synergy between Cu core and ultrathin lead (Pb) shell (0.7 nm) in the Cu/Pb core/shell nanocrystals (NCs, CuPb-0.7/C) significantly boosts the electrocatalytic reduction of CO2 toward C2+ products (products with at least two carbon atoms). Specifically, when applying in a flow cell system, the Faradaic efficiency (FE) of total C2+ products and the selectivity of C2+ liquid products are as high as 81.6% and 49.5%, respectively. Moreover, the current density of C2+ liquid products reaches 196.8 mA cm-2, outperforming most of the reported Cu-based catalysts for CO2RR toward the production of C2+ liquid products. Density functional theory calculations indicate that the synergized Cu/Pb core/shell NCs reduce the formation energies of *COOH and *OCCOH intermediates, as the two critical intermediates for the reduction of CO2 to CO and the formation of C2+ products, respectively, and leads to the significant increase in the selectivity of C2+ liquid products. This study provides a efficient Cu-based catalyst for the reduction of CO2, highlighting the importance of synergistic effect for the design of electrocatalysts in catalysis.

16.
Adv Mater ; 32(40): e2002857, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32864791

RESUMO

Metastable materials are promising because of their catalytic properties, high-energy structure, and unique electronic environment. However, the unstable nature inherited from the metastability hinders further performance improvement and practical applications of these materials. Herein, this limitation is successfully addressed by constructing an in situ polymorphism interface (inf) between the metastable hexagonal-close-packed (hcp) phase and its stable counterpart (face-centered cubic, fcc) in cobalt-nickel (CoNi) alloy. Calculations reveal that the interfacial synergism derived from the hcp and fcc phases lowers the formation energy and enhances stability. Consequently, the optimized CoNi-inf exhibits an exceptionally low potential of 72 mV at 10 mA cm-2 and a Tafel slope of 57 mV dec-1 for the hydrogen evolution reaction (HER) in 1.0 m KOH. Furthermore, it is superior to most state-of-the-art non-noble-metal-based HER catalysts. No noticeable activity decay or structural changes are observed even over 14 h of catalysis. The computational simulation further rationalizes that the interface of CoNi-inf with a suitable d-band center provides uniform sites for hydrogen adsorption, leading to a distinguished HER catalytic activity. This work, therefore, presents a new route for designing metastable catalysts for potential energy conversion.

17.
Chem Soc Rev ; 49(10): 3072-3106, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32309830

RESUMO

Metallic nanostructures with low dimensionality (one-dimension and two-dimension) possess unique structural characteristics and distinctive electronic and physicochemical properties including high aspect ratio, high specific surface area, high density of surface unsaturated atoms and high electron mobility. These distinctive features have rendered them remarkable advantages over their bulk counterparts for surface-related applications, for example, electrochemical water splitting. In this review article, we highlight the recent research progress in low-dimensional metallic nanostructures for electrochemical water splitting including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Fundamental understanding of the electrochemistry of water splitting including HER and OER is firstly provided from the aspects of catalytic mechanisms, activity descriptors and property evaluation metrics. Generally, it is challenging to obtain low-dimensional metallic nanostructures with desirable characteristics for HER and OER. We hereby introduce several typical methods for synthesizing one-dimensional and two-dimensional metallic nanostructures including organic ligand-assisted synthesis, hydrothermal/solvothermal synthesis, carbon monoxide confined growth, topotactic reduction, and templated growth. We then put emphasis on the strategies adopted for the design and fabrication of high-performance low-dimensional metallic nanostructures for electrochemical water splitting such as alloying, structure design, surface engineering, interface engineering and strain engineering. The underlying structure-property correlation for each strategy is elucidated aiming to facilitate the design of more advanced electrocatalysts for water splitting. The challenges and perspectives for the development of electrochemical water splitting and low-dimensional metallic nanostructures are also proposed.

18.
Sci Bull (Beijing) ; 65(5): 350-358, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36659225

RESUMO

The design of electrocatalysts with enhanced adsorption and activation of nitrogen (N2) is critical for boosting the electrochemical N2 reduction (ENR). Herein, we developed an efficient strategy to facilitate N2 adsorption and activation for N2 electroreduction into ammonia (NH3) by vacancy engineering of core@shell structured Au@SnO2 nanoparticles (NPs). We found that the ultrathin amorphous SnO2 shell with enriched oxygen vacancies was conducive to adsorb N2 as well as promoted the N2 activation, meanwhile the metallic Au core ensured the good electrical conductivity for accelerating electrons transport during the electrochemical N2 reduction reaction, synergistically boosting the N2 electroreduction catalysis. As confirmed by the 15N-labeling and controlled experiments, the core@shell Au@amorphous SnO2 NPs with abundant oxygen vacancies show the best performance for N2 electroreduction with the NH3 yield rate of 21.9 µg h-1 mg-1cat and faradaic efficiency of 15.2% at -0.2 VRHE, which surpass the Au@crystalline SnO2 NPs, individual Au NPs and all reported Au-based catalysts for ENR.

19.
Angew Chem Int Ed Engl ; 59(7): 2649-2653, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31765075

RESUMO

Crystal phase engineering is a powerful strategy for regulating the performance of electrocatalysts towards many electrocatalytic reactions, while its impact on the nitrogen electroreduction has been largely unexplored. Herein, we demonstrate that structurally ordered body-centered cubic (BCC) PdCu nanoparticles can be adopted as active, selective, and stable electrocatalysts for ammonia synthesis. Specifically, the BCC PdCu exhibits excellent activity with a high NH3 yield of 35.7 µg h-1 mg-1 cat , Faradaic efficiency of 11.5 %, and high selectivity (no N2 H4 is detected) at -0.1 V versus reversible hydrogen electrode, outperforming its counterpart, face-centered cubic (FCC) PdCu, and most reported nitrogen reduction reaction (NRR) electrocatalysts. It also exhibits durable stability for consecutive electrolysis for five cycles. Density functional theory calculation reveals that strong orbital interactions between Pd and neighboring Cu sites in BCC PdCu obtained by structure engineering induces an evident correlation effect for boosting up the Pd 4d electronic activities for efficient NRR catalysis. Our findings open up a new avenue for designing active and stable electrocatalysts towards NRR.

20.
Acc Chem Res ; 52(12): 3384-3396, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31397995

RESUMO

The development of renewable energy storage and conversion has been greatly promoted by the achievements in platinum (Pt)-based catalysts, which possess remarkable catalytic performance. However, the high cost and limited resources of Pt have hindered the practical applications and thus stimulated extensive efforts to achieve maximized catalytic performance with minimized Pt content. Low dimensional Pt-based bimetallic nanomaterials (such as nanoplates and nanowires) hold enormous potential to realize this target owing to their special atomic arrangement and electronic structures. Recent achievements reveal that strain engineering (e.g., the compressive or tensile strain existing on the Pt skin), surface engineering (e.g., high-index facets, Pt-rich surface, and highly open structures), and interface engineering (e.g., composition-segregated nanostructures) for such nanomaterials can readily lead to electronic modification, more active sites, and strong synergistic effect, thus opening up new avenues toward greatly enhanced catalytic performance. In this Account, we focus on recent advances in low dimensional Pt-based bimetallic nanomaterials as promising catalysts with high activity, long-term stability, and enhanced selectivity for both electrocatalysis and heterogeneous reactions. We begin by illustrating the important role of several strategies on optimizing the catalytic performance: (1) regulated electronic structure by strain effect, (2) increased active sites by surface modification, and (3) the optimized synergistic effect by interfacial engineering. First of all, a difference in atomic bonding strength can result in compressive or tensile force, leading to downshift or upshift of the d-band center. Such effects can be significantly amplified in low-dimensionally confined nanostructures, producing optimized bonding strength for improved catalysis. Furthermore, a high density of high-index facets and a Pt-rich surface in shape-controlled nanostructures based on surface engineering provide further enhancement due to the increased Pt atom utilization and optimal adsorption energy. Finally, interfacial engineering of low dimensional Pt-based bimetallic nanomaterials with high composition-segregation can facilitate the catalytic process due to a strong synergetic effect, which effectively tunes the electronic structure, modifies the coordination environment, and prevents catalysts from serious aggregation. The rational design of low dimensional Pt-based bimetallic nanomaterials with superior catalytic properties based on strain, surface, and interface engineering could help realize enhanced catalysis, gain deep understanding of the structure-performance relationship, and expand access to Pt-based materials for general communities of materials science, chemical engineering, and catalysis in renewable energy research fields.

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