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Ethanol, as a sustainable biomass fuel, is endowed with the merits of theoretically high energy density and environmental friendliness yet suffers from sluggish kinetics and low selectivity toward the desired complete electrooxidation (C1 pathway). Here, the localized surface plasmon resonance (LSPR) effect is explored as a manipulating knob to boost electrocatalytic ethanol oxidation reaction in alkaline media under ambient conditions by appropriate visible light. Under illumination, Au@Pt nanoparticles with plasmonic core and active shell exhibit concurrently higher activity (from 2.30 to 4.05 A mg

In situ spectroscopic characterization of the interfacial structure of an organic additive at a Cu electrode is essential for a mechanistic understanding of Cu superfilling at the molecular level. In this work, we demonstrate wide-frequency attenuated total reflection surface-enhanced infrared absorption spectroscopy (wf-ATR-SEIRAS) to elucidate the dissociative adsorption of bis(sodium sulfopropyl)-disulfide (a typical accelerator) on a Cu electrode in conjunction with the electrochemical quartz crystal microbalance measurement and modeling calculations. The wf-ATR-SEIRAS clearly identifies the peaks featuring the sulfonate and methylene groups as well as the C-S

A balanced detection of both adsorbates and dissolved species is very important for the clarification of the electrochemical reaction mechanism yet remains a major challenge for different modes of electrochemical infrared (IR) spectroscopy. Among others, conventional attenuated total reflection-surface-enhanced IR absorption spectroscopy (ATR-SEIRAS) is far less sensitive to low-concentration solution species than to surface species. We report herein an electrochemical wide-frequency ATR-SEIRAS with a novel thin-layer flow cell design, fulfilling the simultaneous detection of the variations of surface and solution species. This setup consists of a silicon wafer (with one side micromachined and the other side metallized), a thin-layer electrolyte structure with tunable thickness and flow rate, and a tilt-correction system based on laser collimation, enabling a well-controlled mass transport within the electrolyte layer and the spectral differentiation of solution species from adsorbates. Using acidic methanol oxidation on a Pt film electrode as a model system, besides SEIRA bands for adsorbed CO and formate intermediates, IR spectral signals for dissolved products CO

Carotid atherosclerosis by ultrasound scanning can be considered as an ideal window to reflect systemic artery atherosclerosis, which has aroused wide concern for predicting the severity of coronary artery atherosclerosis clinically. Ultrasound radio frequency (RF) data technology has enabled us to evaluate the carotid structure and elastic function precisely, for predicting the severity of coronary artery atherosclerosis.Patients with suspected coronary artery disease (CAD) underwent coronary angiography and were assigned to four groups according to whether atherosclerotic plaque was found or not and it caused stenosis. Carotid artery intima-media thickness (IMT) and arterial stiffness were investigated by quality intima-media thickness (QIMT) and quality arterial stiffness (QAS) techniques during ultrasound scanning. Univariable and multivariable modeling were used to investigate correlations of carotid parameters to coronary artery atherosclerosis. Receive operating characteristic (ROC) curves were used to evaluate diagnostic performance of these ultrasound variables.Carotid IMT and stiffness variables pulse wave velocity (PWV), α, β and compliance coefficient (CC) were statistically different between every two-group's comparisons. IMT correlated with stiffness variables significantly with r = 0.70, 0.77, 0.63, and -0.39, respectively. All variables correlated with the severity of coronary atherosclerosis with the odd ratio (OR) of 1.73, 1.67, 1.19, 1.23, and 0.56 accordingly as IMT, PWV, α, β and CC were concerned. The AUC of IMT, PWV, α, β and CC were 0.9257, 0.8910, 0.8016, 0.9383, 0.8581 with correctly classified rate of 88.16%, 83.77%, 78.07%, 86.84%, and 81.58%, respectively.Carotid artery IMT and stiffness variable PWV, α, β and CC presented favorable predicting and differentiating values for patients with coronary atherosclerosis of different severity.

A wide spectrum of state-of-the-art characterization techniques have been devised to monitor the electrode–electrolyte interface that dictates the performance of electrochemical devices. However, coupling multiple characterization techniques to realize in situ multidimensional analysis of electrochemical interfaces remains a challenge. Herein, we presented a hyphenated differential electrochemical mass spectrometry and attenuated total reflection surface enhanced infrared absorption spectroscopy analytical method via a specially designed electrochemical cell that enables a simultaneous detection of deposited and volatile interface species under electrochemical reaction conditions, especially suitable for non-aqueous, electrolyte-based energy devices. As a proof of concept, we demonstrated the capability of the homemade setup and obtained the valuable reaction mechanisms, by taking the tantalizing reactions in non-aqueous lithium-ion batteries (i.e., oxidation and reduction processes of carbonate-based electrolytes on Li1+xNi0.8Mn0.1Co0.1O2 and graphite surfaces) and lithium-oxygen batteries (i.e., reversibility of the oxygen reaction) as model reactions. Overall, we believe that the coupled and complementary techniques reported here will provide important insights into the interfacial electrochemistry of energy storage materials (i.e., in situ, multi-dimensional information in one single experiment) and generate much interest in the electrochemistry community and beyond.

Adsorbed SO2 on Pt sites can be substituted by NO; adsorbed NO can be completely reduced to NH4+ and removed in a reduction potential range.

Operando differential electrochemical mass spectroscopy investigation reveals the critical microenvironment of electrode surface topology, interfacial electric field and reactant concentration in determining CO2 electrolysis performance.

The interaction between isolated transition-metal atoms and neighboring dopants in single-atom catalysts (SACs) plays a key role in adsorption strength tuning and catalytic performance engineering....

Metal organic frameworks (MOFs) have been extensively investigated in Li-S batteries owing to high surface area, adjustable structures and abundant catalytic sites. Nevertheless, the insulating nature of traditional MOFs render retarded kinetics of polysulfides conversion, leading to insufficient utilization of sulfur. In comparison, conductive MOFs (c-MOFs) show great potential for promoting polysulfides transformation due to superb electronic conductivity. In this work, a nickel-catecholates based c-MOF, Ni-HHTP (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene), is designed to regulate surface chemistry of self-supported carbon paper for advanced Li-S batteries. Taking advantage of the porous structure and high conductivity, the as-prepared Ni-HHTP is conducive to synergising strengthening the chemisorption of polysulfides and accelerating the reaction kinetics in Li-S batteries, significantly mitigating the polysulfides diffusion from the non-encapsulated sulfur cathode, therefore promoting polysulfides transformation in Li-S batteries. This work points out a promising modification strategy for developing advanced sulfur cathode in Li-S batteries.

Copper interconnect electroplating is one of the core technologies for the manufacture of high-end electronic devices including but not limited to chips. To promote the development of advanced copper interconnect process, it is necessary to clarify the mechanisms of copper electroplating additives. Herein, we provide a brief overview of the research progress on the interfacial structures and mechanisms of the three types of additives (accelerator, suppressor and leveler) in copper sulfate plating baths from a methodological perspective. Besides, the advantages and limitations of different research methods are discussed and the scientific issues related to the Damascene copper electroplating are summarized, to afford a hint for the further research and development of the additives in advanced chip fabrication.

Formic acid (HCOOH), as a natural biomass, is a promising feedstock for low temperature fuel cells, and rational development of efficient catalysts for electrochemical dehydrogenation of HCOOH plays a key role toward its full chemical energy utilization. Herein, Pd nanosheets decorated with SnO2 nanoflakes (denoted hereafter as Pd@SnO2-NSs) are designed as a composite catalyst, showing superior performance for formic acid electro-oxidation, as compared to pristine Pd nanosheets (Pd-NSs). In situ attenuated total reflection infrared (ATR-IR) spectroscopic results suggest a promoted formate pathway on the Pd@SnO2-NSs with a suppressed accumulation of CO poisoning species. DFT calculations further indicate that the Pd (1 1 1) surface modified with SnO2 has lower energy barriers for the bidentate formate formation, the bidentate to monodentate formate transformation and the C-H bond scission.

Sodium metal batteries have attracted extensive attentions due to their high energy density and low-cost resources. However, the realization of Na metal anodes is still hampered by intrinsic Na den...

In this study, phosphorus doped graphene supported PtNiP nanocluster electrocatalyst (PtNiP/P-graphene) was successfully prepared via a simple hypophosphite-assisted co-reduction method. The improved anchoring force and increased anchoring sites of graphene support result from phosphorus doping as well as size-confined growth effect of NaH2PO2 leads to uniform dispersion of ultrafine PtNiP nanoclusters. Doped P also promotes the removal of CO-like intermediate by adjusting Pt electronic structure combining with alloyed Ni via electronic effects. As a result, the as-prepared PtNiP/P-graphene catalyst with more exposed active sites and optimized electronic structure of Pt alloy shows excellent electrocatalytic performances for methanol oxidation reaction (MOR) both in activity and durability in an acidic medium.

The electrochemical CO2 reduction reaction (CO2RR) on Pd-based electrodes to dissolved formate and/or gaseous CO is largely dependent on potential and the electrode material, yet there is a lack of...

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt-Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O-H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re-orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode-electrolyte interface during HER and the design of highly efficient HER catalysts.

Sodium metal anodes are commonly limited by low Coulombic efficiency and an unstable interface between Na metal and carbonate ester electrolytes. Herein, a freestanding and implantable artificial p...

Graphene is a promising material in supercapacitors. However, the restacking of graphene sheets during electrode fabrication or under service conditions greatly reduces the capacity for energy storage. Rationally designing a stable and robust 3-D framework of a graphene-based electrode is important for high-performance energy storage devices. Here we demonstrated a novel strategy to engineer the micropore structure in reduced graphene oxide materials for supercapacitors. Anthraquinone molecules as covalently-linked pillars were used to construct graphene framework and prevented the restacking of graphene sheets during fabrication processes. Compared with traditional reduced graphene oxide, the covalently-linked graphene framework contained numerous micropores, and therefore significantly enhanced the performance in supercapacitors. Moreover, this anthraquinone-functionalized graphene framework could also achieve a higher specific capacity in lithium batteries due to the additional Faradaic reaction in oxygen functional groups.

Lithium metal batteries are considered as a “holy grail” of energy storage due to their high energy densities and potential applications in portable electronic devices and electric vehicles. Nevert...

Electro-reforming of renewable biomass resources is an alternative technology for sustainable pure H

Background Acoustic structure quantification (ASQ) has been applied to evaluate liver histologic changes by analyzing the speckle pattern seen on B-mode ultrasound. We aimed to assess the severity of portal hypertension (PHT) through hepatic ultrasonography. Methods Sixty patients diagnosed with PHT and underwent surgical treatment with portosystemic shunts were enrolled. Portal pressure (PP) was measured intraoperatively. Patients were divided into subgroups according to the severity of gastroesophageal varices and Child–Pugh class. Three difference ratio (Cm2) values on ASQ histogram mode were analyzed for their relationships with PP, degree of gastroesophageal varices and Child–Pugh liver function. Thirty healthy volunteers matched with the patients for gender and age were enrolled as controls. Comparisons among groups and correlation of the parameters with PP were analyzed. Area under the receive operating characteristic curve was used to evaluate the predicting value of ASQ parameters. Results In the patients, the ASQ parameters peak Cm2 (Cm2max), mean Cm2 (Cm2mean) and the highest occurred Cm2 value of the obtained red curve (RmaxCm2) were all greatly increased (P P P = 0.027). Multiple comparisons indicated that, regardless of Child–Pugh class and degree of gastroesophageal varices, the patients had significantly increased Cm2max and Cm2mean compared with the controls (all P Cm2max was significantly statistically correlated with PP (r = 0.3505, P r = 0.4998, P Cm2max with a cut-off value of 140.3 for predicting the presence of PHT, gastroesophageal varices and liver function equal to or worse than Child–Pugh class B were 0.8, 0.91 and 0.84, respectively. Conclusions ASQ analysis of ultrasonographic images may have a role in the evaluation of the severity of PHT by detecting liver histologic changes in the speckle pattern caused by cirrhosis.

Heterogeneous catalysis of formic acid dehydrogenation at room temperature is a promising tactic for safely storing and producing H2 as an efficient energy carrier. Up to now, the catalysts for thi...

Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction (ORR) for the application in low temperature fuel cells and beyond, thus their facile and green synthesis is highly demanded. Herein we initially report an alternate aqueous phase one-pot synthesis of such catalysts (containing nominally ca. 20 wt.% Pt) based on dimethylamine borane (DMAB) reduction. The as-obtained electrocatalyst (denoted as Pt3Co/C-DMAB) is compared with the ones obtained by NaBH4 and N2H4·H2O reduction (denoted as Pt3Co/C-NaBH4 and Pt3Co/C-N2H4·H2O, respectively) as well as a commercial Pt/C, in terms of the structure and electrocatalytic property. It turns out that Pt3Co/C-DMAB exhibits the highest ORR performance among all the tested samples in an O2-saturated 0.1 mol/L HClO4, with the mass activity (specific activity) ca. 4 (6) times as large as that for Pt/C. After 10000 cycles of the accelerated degradation test, the half-wave potential for ORR on Pt3Co/C-DMAB decreases only by 4 mV, in contrast to 24 mV for that on Pt/C. Pt3Co/C-NaBH4 or Pt3Co/C-N2H4·H2O shows a specific activity comparable to that for Pt3Co/C-DMAB, but a mass activity similar to that for Pt/C. ICP-AES, TEM, XRD and XPS characterizations indicate that Pt3Co nanoparticles are well-dispersed and alloyed with a mean particle size of ca. 3.4 plusmn; 0.4 nm, contributing to the prominent electrocatalytic performance of Pt3Co/C-DMAB. This simple aqueous synthetic route may provide an alternate opportunity for developing efficient practical electrocatalysts for ORR.

Valorization of CO2 into chemical fuel by photoelectrochemical CO2 reduction competes with hydrogen evolution reaction. Considering that CO2 reduction reaction (CO2RR) occurs on the interface of th...

High-sensitivity and wide-frequency attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) is highly demanded in unraveling electrocatalytic processes at the molecular level. In this work, an in situ ATR-SEIRAS technique incorporating a micromachined Si wafer window, p-polarized infrared radiation, and isotope labeling is extended to revisit the acetaldehyde oxidation reaction (AOR) on a Pt electrode in an acidic medium. New spectral features in the fingerprint region are detected, including ω(C-H) at 1078 cm-1 and νas(C-C-O) at 919 cm-1 for adsorbed acetaldehyde and I´(O-C-O) at 689 cm-1 for adsorbed acetate, besides the other enhanced and clearly discriminated spectral signals at higher frequencies. Time-evolved and potential-dependent ATR-SEIRAS measurements together with advanced density functional theory calculations considering the coadsorption of CO and C2 species enable clarification of the structures and roles of surface C2 intermediates (I·1(C)-acetyl and I·1(H)-acetaldehyde), as reflected by the two bands at 1630 and 1663 cm-1, respectively, leading to updated pathways for the AOR on a Pt electrode.

CO2 electrochemical reduction shows great promise in storing renewable energy and alleviating global warming. Its large-scale applications in the industry, however, are still in infancy mainly due to the unsatisfactory performance of electrocatalysts. Rational design of advanced electrocatalysts would be the ultimate solution, which has yet to be achieved currently because of the lack of understandings of reaction mechanisms. In the past few years, in situ attenuated total reflection infrared (ATR-IR) spectroscopy has been successfully adopted to study the electrochemical interface of the CO2 reduction reaction (CO2RR) and significantly advanced our understandings of this reaction. In this Perspective, these advances as well as the challenges and opportunities faced in further studying CO2RR by this technique are discussed.

In recent years organic ferroelectric/semiconducting blend film has attracted much attention due to its integration of both resistive switching and electrical rectifying properties. In all reported blend structures, P(VDF-TrFE), the copolymer of vinylidene fluoride and trifluoroethylene, is used as the ferroelectric phase, which is blended with organic semiconductors to form phase-separated structure. As another representative ferroelectric polymer, poly(vinylidene fluoride) (PVDF) has its own advantages of even larger polarization and low cost. However, PVDF has much complicated crystalline phases in which its non-polar α phase is the most thermally stable. Effective phase transformation from the α to the ferroelectric phases is still an open question especially for PVDF thin films. Till now seldom work has been reported on PVDF-based ferroelectric/semiconducting resistive films. Here we reported the fabrication and structural and electrical characterizations of PVDF-based ferroelectric/semiconducting ternary resistive films. Poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) was used as semiconducting phase which was phase separated with PVDF phase in PVDF/F8T2 blends. Poly(methyl metacrylate) (PMMA) was introduced into PVDF to promote its ferroelectric γ and β phases. This PVDF/PMMA/F8T2 ternary film showed good resistive switching performance with ON/OFF ratio up to 103, which was comparable to and even larger than those values obtained from blends with P(VDF-TrFE) as the ferroelectric phase. However, the introduction of PMMA also complicateed the basic understanding on phase separation and thus resistive switching mechanism in this ternary film. To clarify this, nanoscale chemical mapping was conducted to distinguish the local distributions of all three phases, the results of which showed obvious nanoscale phase separation in this ternary blend film.

Facile interconversion between CO2 and formate/formic acid (FA) is of broad interest in energy storage and conversion and neutral carbon emission. Historically, electrochemical CO2 reduction reaction to formate on Pd surfaces was limited to a narrow potential range positive of −0.25 V (vs RHE). Herein, a boron-doped Pd catalyst (Pd–B/C), with a high CO tolerance to facilitate dehydrogenation of FA/formate to CO2, is initially explored for electrochemical CO2 reduction over the potential range of −0.2 V to −1.0 V (vs RHE), with reference to Pd/C. The experimental results demonstrate that the faradaic efficiency for formate (ηHCOO–) reaches ca. 70% over 2 h of electrolysis in CO2-saturated 0.1 M KHCO3 at −0.5 V (vs RHE) on Pd–B/C, that is ca. 12 times as high as that on homemade or commercial Pd/C, leading to a formate concentration of ca. 234 mM mg–1 Pd, or ca. 18 times as high as that on Pd/C, without optimization of the catalyst layer and the electrolyte. Furthermore, the competitive selectivity ηHCOO–/η...

Splitting HCOOH (FA) into H2 and CO2 with high turnover frequencies and selectivity is highly desirable for H2 generation and its facilitated utilization. However, the mostly adopted Pd based metallic catalysts are severely suffered from low catalytic efficiency and self-poisoning, owning to the FA dehydration side reaction. Here, we demonstrate firstly that the secret for developing high active and selective Pd towards FAD lies in building abundant Pd-PdO interface at the catalytic surface. Using chemical blocking technique, we identify surface Pd (0) as the active sites for FA adsorption. By combining the density functional theoretical calculations, experiments, and in situ sensitive probes, PdO is found active in fastening the dehydrogenation rate through pulling hydrogen from the reaction intermediates, as well as overcomes CO poisoning by eliminating the self-poisoning dehydration route. Moreover, tetragonal phase PdO/C with minor Pd (0) at the surface is discovered a highly efficient anti-poisoning ...

Mechanistic understanding of electrochemical ammonia oxidation reaction (AOR) is important for designing efficient AOR catalysts. In this work, in situ attenuated total reflection surface-enhanced infrared spectroscopy (ATR-SEIRAS) is employed to study the AOR at varied potentials on an Ir electrode in alkaline media. The AOR on Ir contains two sequential oxidation peaks in the anodic voltammograms. The in situ ATR-SEIRAS results indicate that the small Peak I at a lower potential is mainly due to dehydrogenation of interfacial ammonia and dimerization of as-generated NHx,ad species to N2Hx+y,ad species. And the broad and intense Peak II at a higher potential mainly involves the N2 production from N2Hx+y,ad species, NOad species generation from NHx,ad species and further successive oxidation into the NO2− and NO3− by-products at higher potentials. It is thus inferred that NHx species are the pivotal intermediates for AOR on Ir electrode, and the N2Hx+y,ad and NOad species the key intermediates for the production of N2, NO2− and NO3−, respectively.

Summary Utilizing solar energy to fix CO 2 with water into chemical fuels and oxygen, a mimic process of photosynthesis in nature, is becoming increasingly important but still challenged by low selectivity and activity, especially in CO 2 electrocatalytic reduction. Here, we report transition-metal atoms coordinated in a graphene shell as active centers for aqueous CO 2 reduction to CO with high faradic efficiencies over 90% under significant currents up to ∼60 mA/mg. We employed three-dimensional atom probe tomography to directly identify the single Ni atomic sites in graphene vacancies. Theoretical simulations suggest that compared with metallic Ni, the Ni atomic sites present different electronic structures that facilitate CO 2 -to-CO conversion and suppress the competing hydrogen evolution reaction dramatically. Coupled with Li + -tuned Co 3 O 4 oxygen evolution catalyst and powered by a triple-junction solar cell, our artificial photosynthesis system achieves a peak solar-to-CO efficiency of 12.7% by using earth-abundant transition-metal electrocatalysts in a pH-equal system.

Boron doping can boost the catalytic activity of palladium for diverse reactions. Precise control of the doping content is crucial but remains difficult in current synthesis, which generally involves the use of instable and costly borane-organic compounds. Herein, by taking advantage of the relatively strong solvation of N,N-dimethylformamide (DMF) to Na+ and the increased stability BH4– in DMF, we synthesize B-Pd interstitial nanocrystals in DMF, with NaBH4 acting as a reductant and boron source. The boron content, which can be readily tuned by changing the reaction time and NaBH4 concentration, can reach up to 20 at. %. Such a high boron doping results in a great beneficial effect on the catalytic capability of Pd toward the oxygen reduction reaction (ORR). The synthesized B-Pd nanoalloy exhibits a mass and specific activity for ORR that are, respectively, ca. 14 and 14.6 times higher than those of the state-of-the-art commercial Pt catalyst in alkaline solution. Density functional theory (DFT) calculat...

Cu is the only monometallic catalyst that produces a large amount of hydrocarbon fuels during the CO2 electrochemical reduction reaction (CO2RR). However, the CO2RR mechanism and the impact of electrolyte are unclear. In this communication, two important issues regarding the CO2RR on Cu surfaces are studied: (1) the direct observation on reaction intermediates and (2) the role of the electrolyte (KHCO3) in the reaction. Surface-enhanced infrared absorption spectroscopy allows direct observation of several reaction intermediates that have never been detected before, except for the commonly detected CO. Another important finding is that CO2 molecules are mediated to the Cu surface via their equilibrium with bicarbonate anions instead of direct adsorption from the solution. These results shed light on the full understanding of the CO2RR on Cu surfaces and developing more advanced catalysts.

The effect of chloride anions in electrolyte on formic acid oxidation (FAO) at Pd electrode is investigated by cyclic voltammetry and in situ surface-enhanced infrared absorption spectroscopy with attenuated total reflection (ATR-SEIRAS). Electrochemical measurement indicates that 1–2 × 10 − 5 M Cl − in 0.1 M HClO 4 + 0.1 M HCOOH solution leads to a significant decrease of formic acid oxidation current. Molecular level results from the ATR-SEIRAS indicate that such a small amount of chloride suppresses the adsorption of ClO 4 − and HCO 3 − , increased the CO coverage and somehow stabilized the bidentate formate (HCOO B ) species over the main oxidation potentials. The blocking of active Pd surface sites by Cl − and CO ad is mainly responsible for the oxidation current density decay, and the inconformity of υ(HCOO B ) band intensity and oxidation current implies that HCOO B is probably not the active intermediate in the direct pathway of formic acid oxidation.

Boron-doped platinum-nickel nanoalloy supported on carbon black (Pt3Ni-B/C) is facilely synthesized through an aqueous phase process under mild conditions with dimethylamine borane as the reducing agent. The Pt3Ni-B/C catalyst exhibits an activity toward oxygen reduction reaction (ORR) in acid media at 0.90 V vs. RHE with a mass activity 3 and 1.7 times, and a specific activity 6 and 1.4 times as high as those for a commercial Pt/C and a Pt3Ni/C synthesized using NaBH4 reductant, respectively. After 10,000 cycles of accelerated durability test the Pt3Ni-B/C demonstrates a significantly improved ORR durability in comparison to its counterparts with only 10 mV decay for its half-wave potential. The higher performance of the Pt3Ni-B/C with respect to that of the Pt3Ni/C can be ascribed to well-dispersed and relatively small nanoalloy particles, as well as slightly intensified adsorption strength toward O-containing species and structural resistance to potential cycling with boron doping.

Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles (NPs) in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered the development of efficient catalysts for CO2 electroreduction. Herein, we report the systematic engineering of active phases of Pd NPs, which are exploited to select reaction pathways for CO2 electroreduction. In situ X-ray absorption spectroscopy, in situ attenuated total reflection-infrared spectroscopy, and density functional theory calculations suggest that the formation of a hydrogen-adsorbed Pd surface on a mixture of the α- and β-phases of a palladium-hydride core (α+β PdH x @PdH x ) above −0.2 V (vs. a reversible hydrogen electrode) facilitates formate production via the HCOO* intermediate, whereas the formation of a metallic Pd surface on the β-phase Pd hydride core (β PdH x @Pd) below −0.5 V promotes CO production via the COOH* intermediate. The main product, which is either formate or CO, can be selectively produced with high Faradaic efficiencies (>90%) and mass activities in the potential window of 0.05 to −0.9 V with scalable application demonstration.

Oxygen-containing groups on carbon materials can induce high catalytic activity for some reactions. Herein, on the basis of a series of metal-free single-layer graphene nanodisks (GNDs) with different surface contents of oxygen-containing groups for highly efficient electrocatalytic reduction reaction of CO

It is significantly challenging to stabilize sodium metal anodes in carbonate electrolytes. Here, we report that a sodium metal anode can achieve a high coulombic efficiency of up to ∼97% over 400 cycles at 0.1 mA cm-2 in a carbonate electrolyte with NaAsF6 as an additive. It is revealed that the SEI layer contains a large amount of NaF and O-As-O polymer which enables the stable cycling of sodium metal anodes.