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Abstract: The structure and electrochemical properties of a cobalt-free hydrogen storage electrode alloy LaNi4.05−x Al0.45Mn0.5Fe x (0≤ x ≤0.5) have been investigated with different additions of Fe in replacement of Ni. With the increase of Fe content the maximum discharge capacity gradually decreases from 334.8mAhg−1 to 292.8mAhg−1, however the cycle stability is improved correspondingly. The capacity decay can remain 28.6% (x =0.5) after 300 charge/discharge cycles. The high rate discharge (HRD) ability of the alloys (x ≤0.5) is improved with the increase of Fe content. It is found that all of the alloys are single CaCu5 phase structure disclosed by XRD pattern. However, small amount of the La2O3 phase, observed from SEM photographs, exists on the matrix of all the alloys and when x =0.5, some web-like LaNi2.28 phase is segregated out along the crystal boundary. [Copyright &y& Elsevier]

A low-Co Ml0.8Mg0.2Ni3.2Co0.3Al0.3 alloy was prepared and investigated by examining the alloy structure, phase composition, hydrogen absorption/desorption and electrochemical properties. The alloy is composed of Mg-free LaNi5 phase as matrix and Mg-contained LaNi3 phase as secondary phase. The hydrogen storage capacity (1.37 wt%) at 298 K, discharge capacity (320 mA h/g) and cycling stability (where 88% of the initial capacity remained after 300 charge/discharge cycles) of the alloy are as good as those of the commercial MmNi3.55Co0.75Mn0.4Al0.3 alloy. However, the high-rate discharge ability is better than that of the commercial alloy. The Mn-free composition is advantageous to the oxidization-resistant performance of the alloy. The secondary phase is tougher than the matrix, which not only contributes to the high-rate discharge ability, but also improves the fracture ductility and depresses the disintegration during charge/discharge cycle. [Copyright &y& Elsevier]

• The anthracite-based graphite demonstrates comparable performance to that of commercial graphite. • Taking B 2 O 3 as additive in graphitization process implies the unique catalytic mechanism. • The graphite delivers high capacity of 369 mA h g−1 at 0.05C and superior retention of 98% at 0.5C. The synthetic graphite with higher specific capacity and superior cyclic lifespan is prepared by high temperature graphitization of anthracite coupled with effective catalyst. In the process of graphitization, the thermodynamically unstable carbon atoms orderly convert from disordered structure to graphite crystal structure by thermal activation. However, it is necessary for the graphitization process at high temperature above 2800 °C. The slow reaction speed, low conversion rate, and unmanageable temperature result in a low graphitization degree. Also, B 2 O 3 as catalyst is beneficial to the directional growth of the aromatic layer in graphite structure, which reduces the cross-linking of the aromatic layer and enhances its coplanarity, as well as reduces energy barrier of graphitization and accelerates the formation of graphite phase. When served as anode material for lithium-ion batteries, the material delivers high delithiation capacity of 369 mA h g−1 with first coulomb efficiency (FCE) of 85.3% at 0.05C and even 160 mA h g−1 at 3C. Moreover, at the current density of 0.5 C, the initial capacity still maintains more than 300 mA h g−1 accompanied with almost 98% capacity after 500 cycles. Often, more than 80% of capacity retention at 2 C enables it more competitive and attractive in the fields of anode materials. By matching the graphite as anode and commercial LiFePO 4 as cathode, a full battery is assembled, which still remains the capacity of 93% after nearly 400 cycles, showing cyclic stability of the material. The research provides a direction for the mass production of graphite with coal. [ABSTRACT FROM AUTHOR]

Porous activated carbon material is successfully prepared with anthracite through KOH activation. The obtained activated carbon delivers a large specific surface area of 3550.7 m2 g−1 with existence of porous structure. The KOH activation introduces numerous hydroxyl groups on the surface of carbon material, improving the wettability of carbon. As electrode for supercapacitor, the material delivers the high specific capacity of 433 F g−1 at the current density of 0.5 A g−1 and it maintains 230 F g−1 even current density reaches up to 50 A g−1. Especially, as electrode for symmetric capacitor, the porous activated carbon exhibits a high specific capacitance of 280 F g−1 and energy density of 38.9 Wh kg−1 at 0.5 A g−1. The material also displays superior cyclic stability without distinct decay in capacity after 30000 cycles. The porous activated carbon material derived from coal, which embodies characteristics of capacitance behavior, may broaden the horizon of electrode materials and provide application prospect for specialized hybrid supercapacitor applications. Image 1 • The activated carbon produced by anthracite reveals porous microstructure. • The material delivers an ultrahigh specific surface area of 3550.7 m2 g−1. • The material delivers the high energy density of 38.9 Wh kg−1 at 0.5 A g−1. • The facile prepared route provides the train of thought for practical application. [ABSTRACT FROM AUTHOR]

(1) The NiFeBO is consist of NiFe(OH) 2 layers and BO 2 − pillars. (2) The BO 2 − pillars enhance the stability of NiFe-LDH and show adsorption to hydroxyl ion due to the unsaturated electron state. (3) The addition of Fe and B elements reduces the band gap of α-Ni(OH) 2 , accelerating the catalytic process. (4) The introduced NiFeBO catalyst shows outstanding electrochemical activity for OER with low overpotential, small Tafel slope, and long-term stability. Water-splitting by electrolysis is one of the most important approaches to produce hydrogen as renewable clean energy with superior advantages of high-purity and good operability. But the key issue limiting the large-scale application is that it demands a much higher overpotential than the theoretical oxygen evolution potential. Herein, we report an efficient electrochemical catalyst of NiFeBO synthesized via a facile one-step process, presenting remarkable catalytic activity and long-term stability. In this work, we discussed the effects of the doping of Fe and the insertion of BO 2 − in the as-synthesized NiFeBO. According to the experimental results, NiFeBO shows a very low overpotential of 256 mV and a Tafel slope of 53 mV dec−1 with remarkable stability over 60 h of chronopotentiometry test. The inserted anion of BO 2 − can adsorb OH− in electrolyte around the catalyst to increase the concentration of OH− around the active sites, thereby improving the effectivity of oxygen evolution reaction. In addition, diffused micro-crystalline with different lattice formed during the oxidation of the as-synthesized catalyst, providing more active sites than the pristine amorphous. [ABSTRACT FROM AUTHOR]

Ultrahigh strength can be obtained by cold drawing of high-carbon steel wire, but the strength heavily relies on the extent of cold-drawn deformation and it is difficult to produce ultrahigh strength steel wire with large diameter. In this study, a new method by combination of cold-drawing and martensitic transformation was reported to significantly improve the strength of cold-drawn steel wire. By using the new method, the strength of the steel wire can be increased to over 2.4 GPa, which is much higher than its corresponding original cold-drawn wire (less than 2.0 GPa), while sacrificing only a small ductility. By using electrochemical etching, transmission electron microscopy and X-ray diffraction, the prior austenite grain size and the microstructure of the martensitic steel wires was analysed. After the heat treatment, the large cold deformed steel wire with 8 pass drawing displays grains of 4.9 μm and dislocation-substructured martensite; while the small cold deformed wire with 6 pass drawing results in coarser grains and a mixture substructure of dislocation and twin in martensite. The results demonstrate that the extent of cold-drawn deformation has a great influence on grain refinement in the later heat treatment; grain refinement to less than 5 μm will lead to martensite substructure transition from twin to dislocation, and thus endows the martensitic steel wire moderate ductility. In addition, calculation indicates that precipitate hardening and dislocation strengthening contribute about 76.9% to the yield strength, and martensite lath boundary strengthening contributes about 18% to the yield strength. • A new method to improve strength of cold-drawn steel wire was proposed. • Large cold-drawn strain promotes grain refinement during heat treatment process. • Grain refining promotes martensite substructure transition from twin to dislocation. • Dislocation-structured martensite endows martensitic steel wire moderate ductility. • The ultrahigh strength mainly comes from dislocation and precipitation strengthening. [ABSTRACT FROM AUTHOR]

A lamella structured low-carbon steel plate with bimodal grain size distribution (LSBG steel) was produced by a two-step warm rolling and subsequently annealing, and its mechanical properties, strengthening and toughening mechanisms were studied. The heterogeneous lamellar structure is characterized with ultrafine-grained (UFG) lamellae (with average grain diameter about 1 μm) embedded in coarse-grained (CG) lamellae matrix. The LSBG steel shows an improved combination of strength and toughness when compared with corresponding CG specimens, and also evades strength-ductility trade-off compared with UFG ones. When comparing with initial CG steel, the yield strength and tensile strength are increased by 87.4% and 35% respectively, but the ductility is only with a small sacrifice, and the ductile-to-brittle transition temperature is significantly decreased from about −70 °C to −110 °C. The improved strength is mainly attributed to ultrafine grain strengthening, and the reasonable ductility can be attributed to both the bimodal grain size and the lamellar structure as they can increase the work hardening rate by the accumulation of geometrically necessary dislocations in their vicinity. And the improved toughness of the LSBG steel is thought to be mainly attributed to grain refinement and the lamellar structure. Image 1 • Lamella structured steel with bimodal grain size distribution (LSBG) was produced. • The LSBG steel shows an improved combination of strength and toughness. • Both grain refinement and the lamellar structure contribute to strength improvement. • Bimodal grain size and the lamellar structure contribute to good ductility. • Toughness improvement of the LSBG steel is mainly attributed to grain refinement. [ABSTRACT FROM AUTHOR]

• The bainite transformation behavior of ultrafine grained steel was studied. • Bainite transformation is greatly retarded in UFG 65Cr steel. • Upper bainite transformation temperature is lowered in UFG 65Cr steel. Isothermal bainite transformation was conducted on both ultrafine-grained (UFG) and normal-grained (NG) 65Cr steels. Both bainite morphology and transformation rate are greatly influenced by prior austenite grain size. Bainite transformation rate is greatly retarded in the UFG steel with average grain size of 4.6 μm. Lower bainite was obtained for both UFG and NG steels when austempered at 250 °C and 300 °C; however, the bainite morphology changed from lower to upper banite for UFG steel when austempered at 400 °C, and lower bainite was still obtained in NG steel. This phenomenon is caused by austenite yield strength increase due to grain refinement. [ABSTRACT FROM AUTHOR]

The metal-nitrogen-carbon (M-N-C)-based catalysts are promising to replace PGM (platinum group metal) to accelerate oxygen reduction reaction due to their excellent electrocatalytic performance. However, the inferior intrinsic activity and poor active site density confining further improvement in their performance. Modulating the electronic structure and reasonably designing the pore structure are widely acknowledged effective strategies to boost the activity of the M-N-C catalysts. However, it is a great challenge to form abundant pores to regulate the electronic structure via the facile method. Herein, a hierarchical, porous dual-atom catalyst FeNi-NPC-1000 has been architectured by the Na 2 CO 3 template method and bimetallic doping modification strategy. Benefitting from the optimized pore and electronic structure, the as-prepared FeNi-NPC-1000 possesses a high specific surface area (1412.8 m 2 g -1 ) and improved ORR activity ( E 1/2 = 0.877 V vs RHE), which is superior to that of Pt/C ( E 1/2 = 0.867 V vs RHE). With the evidence of AC-STEM, XAS, and DFT, the FeNi-N 8 -C moiety is proven to be the key active site to realize high-efficiency ORR catalysis. When assembled it as an air cathode of ZABs, FeNi-NPC-1000 displays superior discharge performance ( P max = 367.1 mW cm -2 ) and a stable battery long-life. This article will provide a new strategy for designing dual-metal atomic catalysts applied in metal-air batteries.

Oxygen electrocatalysis has aroused considerable interest over the past years because of the new energy technologies boom in hydrogen energy and metal-air battery. However, due to the sluggish kinetic of the four-electron transfer process in oxygen reduction reaction and oxygen evolution reaction, the electro-catalysts are urgently needed to accelerate the oxygen electrocatalysis. Benefit from the high atom utilization efficiency, unprecedentedly high catalytic activity, and selectivity, single-atom catalysts (SACs) are considered the most promising candidate to replace the traditional Pt-group-metal catalysts. Compared with SACs, the dual-atom catalysts (DACs) are attracting more attraction including higher metal loading, more versatile active sites, and excellent catalytic activity. Therefore, it is essential to explore the new universal methods approaching to the preparation, characterization, and to elucidate the catalytic mechanisms of the DACs. In this review, several general synthetic strategies and structural characterization methods of DACs are introduced and the involved oxygen catalytic mechanisms are discussed. Moreover, the state-of-the-art electrocatalytic applications including fuel cells, metal-air batteries, and water splitting have been sorted out at present. The authors hope this review has given some insights and inspiration to the researches about DACs in electro-catalysis., (© 2023 Wiley-VCH GmbH.)

The low conductivity of sulfur and the shuttle effect of lithium polysulfides (LiPSs) are the two intrinsic obstacles that limit the application of lithium-sulfur batteries (LSBs). Herein, a sulfur vacancy introduced NiCo 2 S 4 nanosheet array grown on carbon nanofiber (CNF) membrane (NiCo 2 S 4-x /CNF) is proposed to serve as a self-supporting and binder-free interlayer in LSBs. The conductive CNF skeleton with a non-woven structure can effectively reduce the resistance of the cathode and accommodate volume expansion during charge-discharge process. The bonding between CNF matrix and NiCo 2 S 4 nanosheet is enhanced by in situ growth, ensuring fast electron transfer. Besides, the sulfur vacancies in NiCo 2 S 4 enhance the chemisorption of LiPSs, and the highly active sites at vacancies can accelerate the LiPSs conversion kinetics. LSB paired with NiCo 2 S 4-x /CNF interlayer achieved improved stability in 500 cycles at 0.2 C and long life of 3000 cycles at 3 C. More importantly, a high areal capacity of 9.69 mAh cm -2 is achieved with a sulfur loading of 10.8 mg cm -2 and a low electrolyte to sulfur (E/S) ratio of 4.8. This work provides insight into the sulfur vacancy in catalysis design for LiPSs conversion and demonstrates a promising direction for electronic defect engineering in material design for LSBs., (© 2023 Wiley-VCH GmbH.)

Platinum group metal (PGM)-free M-N-C catalysts have exhibited dramatic electrocatalytic performance and are considered the most promising candidate of the Pt catalysts in oxygen reduction reaction (ORR). However, the electrocatalytic performance of the M-N-C catalysts is still limited by their inferior intrinsic activity and finite active site density. Regulating the coordination environment and increasing the pore structure of the catalyst is an effective strategy to enhance the electrocatalytic performance of the M-N-C catalysts. In this work, the coordination environment and pore structure exquisitely regulated Fe-N-C catalyst exhibit excellent ORR activity and durability. With the enhanced intrinsic activity and increased active site density, the optimized Fe-N/S-C catalyst shows impressive ORR activity (E 1/2  = 0.904 V vs reversible hydrogen electrode (RHE)) and superior long-term durability in an alkaline medium. As the advanced physical characterization and theoretical chemistry methods illustrate, the S-modified Fe-N x (Fe-N 3 /S-C) moiety is confirmed as the improved active center for ORR, and the increased active site density further improved ORR efficiency. Based on the Fe-N/S-C cathode, a Zn-air battery is fabricated and shows superior power density (315.4 mW cm -2 ) and long-term discharge stability at 20 mA cm -2 . This work would open a new perspective to design atomically dispersed iron-metal site catalysts for advanced electro-catalysis., (© 2022 Wiley-VCH GmbH.)

Lithium-sulfur (Li-S) batteries have attracted considerable attention owing to their extremely high energy densities. However, the application of Li-S batteries has been limited by low sulfur utilization, poor cycle stability, and low rate capability. Accelerating the rapid transformation of polysulfides is an effective approach for addressing these obstacles. In this study, a defect-rich single-atom catalytic material (Fe-N4/DCS) is designed. The abundantly defective environment is favorable for the uniform dispersion and stable existence of single-atom Fe, which not only improves the utilization of single-atom Fe but also efficiently adsorbs polysulfides and catalyzes the rapid transformation of polysulfides. To fully exploit the catalytic activity, catalytic materials are used to modify the routine separator (Fe-N 4 /DCS/PP). Density functional theory and in situ Raman spectroscopy are used to demonstrate that Fe-N 4 /DCS can effectively inhibit the shuttling of polysulfides and accelerate the redox reaction. Consequently, the Li-S battery with the modified separator achieves an ultralong cycle life (a capacity decay rate of only 0.03% per cycle at a current of 2 C after 800 cycles), and an excellent rate capability (894 mAh g -1 at 3 C). Even at a high sulfur loading of 5.51 mg cm -2 at 0.2 C, the reversible areal capacity still reaches 5.4 mAh cm -2 ., (© 2022 Wiley-VCH GmbH.)

High energy density and long cycle life of lithium-sulfur (Li-S) batteries suffer from the shuttle/expansion effect. Sufficient sulfur storage space, local fixation of polysulfides, and outstanding electrical conductivity are crucial for a robust cathode host. Herein, a modified template method is proposed to synthesize a highly regular and uniform nitrogen/oxygen dual-doped honeycomb-like carbon as sulfur host (N/O-HC-S). The unique structure not only offers physical entrapment for polysulfides (LiPSs) but also provides chemical adsorption and catalytic conversion sites of polysulfides. In addition, this structure offers enough space for loading sulfur, and a regular space of nanometer size can effectively prevent sulfur particles from accumulating. As expected, the as-prepared N/O-HC900-S with high areal sulfur loading (7.4 mg cm -2 ) shows a high areal specific capacity of 7.35 mAh cm -2 at 0.2 C. Theoretical calculations also reveal that the strong chemical immobilization and catalytic conversion of LiPSs attributed to the spin density and charge distribution of carbon atoms will be influenced by the neighbor nitrogen/oxygen dopants. This structure that provides cooperative chemical adsorption, high lithium ions flux, and catalytic conversion for LiPSs can offer a new strategy for constructing a polysulfide confinement structure to achieve robust Li-S batteries., (© 2022 Wiley-VCH GmbH.)

α-Ni(OH) 2 is an ideal candidate material for a supercapacitor except for its low conductivity and poor stability. In this work, BO 2 - -intercalated α-Ni x Co (1- x ) (OH) 2 is synthesized by a hydrothermal method at a low cost. The Co dopant can decrease the charge-transfer resistance and enhance the cyclic stability. The special unsaturated electronic state of BO 2 - enhances the bonding with metal ions and attracts water molecules. Thus, the BO 2 - ions support the hydroxide layers as pillars and create efficient paths for proton transportation, optimizing the utilization of α-Ni(OH) 2 . The three-dimensional (3D) flowerlike morphology supplies an enormous number of active sites, and r-GO is added to improve the conductivity. As a result, the modified α-Ni(OH) 2 exhibits the specific capacitance of 2179, 1592, and 1423 F·g -1 at 1, 20, and 40 A·g -1 , respectively, showing improved rate performance. Matching with the commercial activated carbon (AC) as an anode, the asymmetric capacitor delivers an energy density of 40.66 W·h·kg -1 when its power density is 187.06 W·kg -1 . Meanwhile, it retains 81.5% capacitance of the initial cycle at 5 A·g -1 after 3000 cycles. With conductivity enhanced and structure stabilized, the modified α-Ni(OH) 2 confronts broader fields of application.

A H 2 /CO 2 fuel cell is a promising device that can convert CO 2 into hydrocarbon fuel with electricity generation. Herein, a facile electrospinning method has been used to synthesize the embedded Ru-CNF catalyst in which Ru nanoparticles are dispersed homogeneously within N-doped carbon nanofibers. This catalyst exhibits a high CH 4 production rate of 308.46 μmol g cat -1 h -1 at 170 °C, which is superior to that of the Ru/CNF (242.53 μmol g cat -1 h -1 ) and Ru/CNT (194.24 μmol g cat -1 h -1 ). The enhanced CO 2 RR performance of Ru-CNF is ascribed to the well-distributed Ru nanoparticles within the CNF matrix and synergistic effect of Ru sites with N species, which results in forming the increased CO 2 RR active sites, hence improving the catalytic activity. Simultaneously, it can achieve a peak power density of 1.8 W m -2 on the strength of anodic (H 2 oxidation) and cathodic (CO 2 reduction and H 2 evolution) reactions with remarkable stability. Such findings give a theoretical basis of CO 2 RR in the H 2 /CO 2 fuel cell system, which could hold great value to further develop the high-efficiency catalysts for CO 2 reduction.

The abundant reserve and low price of potassium resources promote K-ion batteries (KIBs) becoming a promising alternative to Li-ion batteries, while the large ionic radius of K-ions creates a formidable challenge for developing suitable electrodes. Here Ni-substituted Prussian blue analogues (PBAs) are investigated comprehensively as cathodes for KIBs. The synthesized K 1.90 Ni 0.5 Fe 0.5 [Fe(CN) 6 ] 0.89 ·0.42H 2 O (KNFHCF-1/2) takes advantage of the merits of high capacity from electrochemically active Fe-ions, outstanding electrochemical kinetics induced by decreased band gap and K-ion diffusion activation energy, and admirable structure stability from inert Ni-ions. Therefore, a high first capacity of 81.6 mAh·g -1 at 10 mA·g -1 , an excellent rate property (53.4 mAh·g -1 at 500 mA·g -1 ), and a long-term lifespan over 1000 cycles with the lowest fading rate of 0.0177% per cycle at 100 mA·g -1 can be achieved for KNFHCF-1/2. The K-ion intercalation/deintercalation proceeds through a facile solid solution mechanism, allowing 1.5-electron transfer based on low- and high-spins Fe II /Fe III couples, which is verified by ex situ XRD, XPS, and DFT calculations. The K-ion full battery is also demonstrated using a graphite anode with a high energy density of 282.7 Wh·kg -1 . This work may promote more studies on PBA electrodes and accelerate the development of KIBs.

Background: Little empirical evidence is known about the sleep quality of frontline health professionals working in isolation units or hospitals during the novel coronavirus disease (COVID-19) outbreak in China. This study thus aimed to examine the prevalence of poor sleep quality and its demographic and correlates among frontline health professionals., Methods: This is a multicenter, cross-sectional survey conducted in Liaoning province, China. Sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI)., Results: A total of 1,931 frontline health professionals were recruited. The prevalence of poor sleep quality was 18.4% (95%CI: 16.6%-20.11%). Multivariate logistic regression analysis found that older age (OR=1.043, 95%CI=1.026-1.061, P < 0.001), being nurse (OR=3.132, 95%CI=1.727-5.681, P < 0.001), and working in outer emergency medical team (OR=1.755, 95%CI=1.029-3.064, P =0.039) were positively associated with poor sleep quality. Participants who were familiar with crisis response knowledge were negatively associated with poor sleep quality (OR=0.70, 95%CI=0.516-0.949, P =0.021)., Conclusion: The prevalence of poor sleep quality was relatively low among frontline health professionals during the COVID-19 epidemic. Considering the negative impact of poor sleep quality on health professionals' health outcomes and patient outcomes, regularly screening and timely treatments are warranted to reduce the likelihood of poor sleep quality in health professionals., (Copyright © 2020 Zhou, Yang, Shi, Song, Zhou, Zhang, Guo, Li, Liu, Xu, Cheung, Xiang and Tang.)

Tris(pentafluorophenyl) borane (C 18 BF 15 ) was first adopted as a boron source, which clearly demonstrated its modification effects. XPS and EDX mapping proved that boron can be successfully doped into a carbon layer. The high number of defects in the carbon induced by boron was demonstrated via Raman spectroscopy and thus, the electric conductivity of LiFePO 4 was greatly enhanced. The boron-doped composite possessed a higher specific discharge capacity and rate capability than the undoped sample. For instance, the reversible specific capacity for the boron-doped cathode reached 165.8 mA h g -1 at 0.5C, which was almost close to its theoretical capacity (166 mA h g -1 ). Even at a high rate of 5C, it still possessed a high specific capacity of 124.8 mA h g -1 . This provides for the possibility that boron-doped carbon-coated LiFePO 4 cathodes may deliver high energy and power density for rechargeable lithium-ion batteries., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Deactivation of an anode catalyst resulting from the poisoning of CO ad -like intermediates is one of the major problems for methanol and ethanol electro-oxidation reactions (MOR & EOR), and remains a grand challenge towards achieving high performance for direct alcohol fuel cells (DAFCs). Herein, we report a new approach for the preparation of ultrafine cobalt-doped CeO 2 dots (Co-CeO 2 , d = 3.6 nm), which can be an effective anti-poisoning promoter for Pd catalysts towards MOR and EOR in alkaline media. Compared to Pd/CeO 2 and pure Pd, the hybrid Pd/Co-CeO 2 nanocomposite catalyst exhibited a much enhanced activity and remarkable anti-poisoning ability for both MOR and EOR. The nanocomposite catalyst showed much higher mass activity (4×) than a state-of-the-art PtRu catalyst. The promotional mechanism was elucidated using extensive characterization and density-functional theory (DFT). A bifunctional effect of the Co-CeO 2 dots was discovered to be due to (i) an enhanced electronic interaction between Co-CeO 2 and Pd dots and (ii) the increased oxygen storage capacity of Co-CeO 2 dots to facilitate the oxidation of CO ad . Therefore, the Pd/Co-CeO 2 nanocomposite appears to be a promising catalyst for advanced DAFCs with low cost and high performance.