FeN4 Active Sites Electronically Coupled with PtFe Alloys for Ultralow Pt Loading Hybrid Electrocatalysts in Proton Exchange Membrane Fuel Cells.

The exorbitant cost of Pt-based electrocatalysts and the poor durability of non-noble metal electrocatalysts for proton exchange membrane fuel cells limited their practical application. Here, FeN4 active sites electronically coupled with PtFe alloys (PtFe-FeNC) were successfully prepared by a vapor deposition strategy as an ultralow Pt loading (0.64 wt %) hybrid electrocatalyst. The FeN4 sites on the FeNC matrix are able to effectively anchor the PtFe alloys, thus inhibiting their aggregation during long-life cycling. These PtFe alloys, in turn, can efficiently restrain the leaching of the FeN4 sites from the FeNC matrix. Thus, the PtFe-FeNC demonstrated an improved Pt mass activity of 2.33 A mgPt-1 at 0.9 V toward oxygen reduction reaction, which is 12.9 times higher than that of commercial Pt/C (0.18 A mgPt-1). It demonstrated great stability, with the Pt mass activity decreasing by only 9.4% after 70,000 cycles. Importantly, the fuel cell with an ultralow Pt loading in the cathode (0.012 mgPt cm-2) displays a high Pt mass activity of 1.75 A mgPt-1 at 0.9 ViR-free, which is significantly better than commercial MEA (0.25 A mgPt-1). Interestingly, PtFe-FeNC catalysts possess enhanced durability, exhibiting a 12.5% decrease in peak power density compared to the 51.7% decrease of FeNC.

Ga-Modification Near-Surface Composition of Pt-Ga/C Catalyst Facilitates High-Efficiency Electrochemical Ethanol Oxidation through a C2 Intermediate.

In electrochemical ethanol oxidation reactions (EOR) catalyzed by Pt metal nanoparticles through a C2 route, the dissociation of the C-C bond in the ethanol molecule can be a limiting factor. Complete EOR processes producing CO2 were always exemplified by the oxidative dehydrogenation of C1 intermediates, a reaction route with less energy utilization efficiency. Here, we report a Pt3Ga/C electrocatalyst with a uniform distribution of Ga over the nanoparticle surface for EOR that produces CO2 at medium potentials (>0.3 V vs SCE) efficiently through direct and sustainable oxidation of C2 intermediate species, i.e., acetaldehyde. We demonstrate the excellent performance of the Pt3Ga-200/C catalyst by using electrochemical in situ Fourier transform infrared reflection spectroscopy (FTIR) and an isotopic labeling method. The atomic interval structure between Pt and Ga makes the surface of nanoparticles nonensembled, avoiding the formation of poisonous *CHx and *CO species via bridge-type adsorption of ethanol molecules. Meanwhile, the electron redistribution from Ga to Pt diminishes the *O/*OH adsorption and CO poisoning on Pt atoms, exposing more available sites for interaction with the C2 intermediates. Furthermore, the dissociation of H2O into *OH is facilitated by the high hydrophilicity of Ga, which is supported by DFT calculations, promoting the deep oxidation of C2 intermediates. Our work represents an extremely rare EOR process that produces CO2 without observing kinetic limitations under medium potential conditions.

Cefoperazone sodium/sulbactam sodium vs piperacillin sodium/tazobactam sodium for treatment of respiratory tract infection in elderly patients.

BACKGROUND: Respiratory tract infections in the elderly are difficult to cure and can easily recur, thereby posing a great threat to patient prognosis and quality of life. AIM: To investigate the therapeutic effects of different antibiotics in elderly patients with respiratory tract infection. METHODS: Seventy-four elderly patients with respiratory tract infection were randomly allocated to a study (n = 37; treated with cefoperazone sodium/sulbactam sodium) or control (n = 37; treated with piperacillin sodium/tazobactam sodium on the basis of routine symptomatic support) group. Both groups were treated for 7 d. Time to symptom relief (leukocyte recovery; body temperature recovery; cough and sputum disappearance; and rale disappearance time), treatment effect, and laboratory indexes [procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC), and neutrophil percentage (NE)] before and 7 d after treatment and the incidence of adverse reactions were assessed. RESULTS: In the study group, the time to WBC normalization (6.79 ± 2.09 d), time to body temperature normalization (4.15 ± 1.08 d), time to disappearance of cough and sputum (6.19 ± 1.56 d), and time to disappearance of rales (6.68 ± 1.43 d) were shorter than those of the control group (8.89 ± 2.32 d, 5.81 ± 1.33 d, 8.77 ± 2.11 d, and 8.69 ± 2.12 d, respectively; P = 0.000). Total effective rate was higher in the study group (94.59% vs 75.68%, P = 0.022). Serum PCT (12.89 ± 3.96 µg/L), CRP (19.62 ± 6.44 mg/L), WBC (20.61 ± 6.38 × 109/L), and NE (86.14 ± 7.21%) levels of the study group before treatment were similar to those of the control group (14.05 ± 4.11 µg/L, 18.79 ± 5.96 mg/L, 21.21 ± 5.59 × 109/L, and 84.39 ± 6.95%, respectively) with no significant differences (P = 0.220, 0.567, 0.668, and 0.291, respectively). After 7 d of treatment, serum PCT, CRP, WBC, and NE levels in the two groups were lower than those before treatment. Serum PCT (2.01 ± 0.56 µg/L), CRP (3.11 ± 1.02 mg/L), WBC (5.10 ± 1.83 × 109/L), and NE (56.35 ± 7.17%) levels were lower in the study group than in the control group (3.29 ± 0.64 µg/L, 5.67 ± 1.23 mg/L, 8.13 ± 3.01 × 109/L, and 64.22 ± 8.08%, respectively; P = 0.000). There was no significant difference in the incidence of adverse reactions between the groups (7.50% vs 12.50%, P = 0.708). CONCLUSION: Piperacillin sodium/tazobactam sodium is superior to cefoperazone sodium/ sulbactam sodium in the treatment of elderly patients with respiratory tract infection with a similar safety profile.

Interfacial Structure of Water as a New Descriptor of the Hydrogen Evolution Reaction.

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.

Construction of Highly Active Metal-Containing Nanoparticles and FeCo-N4 Composite Sites for the Acidic Oxygen Reduction Reaction.

Metal-containing nanoparticles (M-NPs) in metal/nitrogen-doped carbon (M-N-C) catalysts have been considered hostile to the acidic oxygen reduction reaction (ORR). The relation between M-NPs and the active sites of metal coordinated with nitrogen (MNx ) is hard to establish in acid medium owing to the poor stability of M-NPs. Herein, we develop a strategy to successfully construct a new FeCo-N-C catalyst containing highly active M-NPs and MN4 composite sites (M/FeCo-SAs-N-C). Enhanced catalytic activity and stability of M/FeCo-SAs-N-C is shown experimentally. Calculations reveal that there is a strong interaction between M-NPs and FeN4 sites, which can favor ORR by activating the O-O bond, thus facilitating a direct 4 e- process. Those findings firstly shed light on the highly active M-NPs and FeN4 composite sites for catalyzing acid oxygen reduction reaction, and the relevant reaction mechanism is suggested.

Flavins mediate extracellular electron transfer in Gram-positive Bacillus megaterium strain LLD-1.

The extracellular electron transfer (EET) mechanism of an isolated Gram-positive Bacillus megaterium strain (LLD-1), identified by 16S rRNA gene sequencing and physiological analysis, was investigated in the present study. The electrochemical activity of strain LLD-1 was confirmed by electrochemical E-t and amperometric I-t tests. Flavins in culture suspension from strain LLD-1 were further proved to be able to act as electron shuttles, strengthening the electron transfer from LLD-1 to the electrode. The output voltage and current output were increased 2.8 times and 3.7 times, respectively, by adding 100nM exogenetic flavins into microbial fuel cells inoculated with LLD-1. Electricity generation by LLD-1 from different carbon sources can be enhanced by adding 100nM exogenetic flavins. This study indicated that flavins were essential to the EET process of the Gram-positive strain LLD-1. Furthermore, a putative EET model for B. megaterium strain LLD-1 and even for Gram-positive bacteria was proposed.

Structure Design and Performance Tuning of Nanomaterials for Electrochemical Energy Conversion and Storage.

The performance of nanomaterials in electrochemical energy conversion (fuel cells) and storage (secondary batteries) strongly depends on the nature of their surfaces. Designing the structure of electrode materials is the key approach to achieving better performance. Metal or metal oxide nanocrystals (NCs) with high-energy surfaces and open surface structures have attained significant attention in the past decade since such features possess intrinsically exceptional properties. However, they are thermodynamically metastable, resulting in a huge challenge in their shape-controlled synthesis. The tuning of material structure, design, and performance on the nanoscale for electrochemical energy conversion and storage has attracted extended attention over the past few years. In this Account, recent progress made in shape-controlled synthesis of nanomaterials with high-energy surfaces and open surface structures using both electrochemical methods and surfactant-based wet chemical route are reviewed. In fuel cells, the most important catalytic materials are Pt and Pd and their NCs with high-energy surfaces of convex or concave morphology. These exhibit remarkable activity toward electrooxidation of small organic molecules, such as formic acid, methanol, and ethanol and so on. In practical applications, the successful synthesis of Pt NCs with high-energy surfaces of small sizes (sub-10 nm) realized a superior high mass activity. The electrocatalytic performances have been further boosted by synergetic effects in bimetallic systems, either through surface decoration using foreign metal atoms or by alloying in which the high-index facet structure is preserved and the electronic structure of the NCs is altered. The intrinsic relationship of high electrocatalytic performance dependent on open structure and high-energy surface is also valid for (metal) oxide nanomaterials used in Li ion batteries (LIB). It is essential for the anode nanomaterials to have optimized structures to keep them more stable during the charge/discharge processes for reducing damaging volume expansion via intercalation and subsequent reduced battery lifetime. In the case of cathodes, tuning the surface structure of nanomaterials should be one of the most beneficial strategies to enhance the capacity and rate performance. In addition, metal oxides with unique defective structure of high catalytic activity and carbon materials of porous structure for facilitating fast Li+ diffusion paths and efficiently trapping polysulfide are most important approached and employed in Li-O2 battery and Li-S battery, respectively. In summary, significant progress has already been made in the electrocatalytic field, and likely emerging techniques based on NCs enclosed with high-energy surfaces and high-index facets could provide a promising platform to investigate the surface structure-catalytic functionality at nanoscale, thus shedding light on the rational design of practical catalysts with high activity, selectivity, and durability for energy conversion and storage.

Anastomosing hemangioma arising from the kidney: a case of slow progression in four years and review of literature.

Reported herein is a renal anastomosing hemangioma which developed slowly in the past four years. A 25-year-old woman was found a mass localized in the upper portion four years ago, and only slow progression in the past four years. She underwent a laparoscopic partial nephrectomy of right kidney and diagnosed as anastomosing hemangioma. On histology the vascular components of the tumor had an anastomosing pattern without well-definite margins. Immunohistochemically, only endothelial markers (CD31, CD34) were expressed on the vascular components of tumor cells. Smooth muscle actin (SMA), cytokeratin (CK), EMA and S-100 and so on were all negative in the epithelioid tumor cells. The patient was alive at 16 months after operation, without any evidence recurrence or metastasis. Anastomosing hemangioma is an extremely rare vascular neoplasm; only 23 cases were previously described until now. Our report of anastomosing hemangioma arising from the kidney with slow progression will improve the knowledge of primary vascular tumors arising in the kidney.

Simultaneous double primary clear cell carcinomas of liver and kidney: a case report and review of literature.

Reported herein are simultaneous double primary clear cell carcinomas arising from liver and kidney. A 63-year-old man underwent a partial wedge nephrectomy of the right kidney in a surgical resection for hepatocellular carcinoma. Coincidently, on histology the tumors in liver and kidney were consisted of clear cancer cells, which arranged in haphazardly intermixed pattern without capsules. Immunohistochemically, the clear neoplastic cells in the liver were positive for HepPar-1, GPC3, and negative for nephrogenic markers; however, renal clear neoplastic cells were positive for CD10, RCC and Pax-8, but negative to liver-derived markers. These findings led to the diagnosis of simultaneous double primary clear cell carcinomas of kidney and liver. Multiple primary carcinomas of kidney and liver, especially both are primary clear cell carcinomas, are extremely rare neoplasms, only 1 case has been reported previously until now. To our knowledge, this is a report of multiple primary carcinomas arising from the liver and kidney and reminders us of differentiation diagnosis with carcinoma metastasis.

Platelet-rich plasma in arthroscopic rotator cuff repair: a meta-analysis of randomized controlled trials.

PURPOSE: The purpose of this study was to appraise the retear rate and clinical outcomes of platelet-rich plasma use in patients undergoing arthroscopic full-thickness rotator cuff repair. METHODS: We searched the Cochrane Library, PubMed, and EMBASE databases for randomized controlled trials comparing the outcomes of arthroscopic rotator cuff surgery with or without the use of platelet-rich plasma. Methodological quality was assessed by the Detsky quality scale. When there was no high heterogeneity, we used a fixed-effects model. Dichotomous variables were presented as risk ratios (RRs) with 95% confidence intervals (CIs), and continuous data were measured as mean differences with 95% CIs. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the quality of evidence for each individual outcome. RESULTS: Eight randomized controlled trials were included, with the sample size ranging from 28 to 88. Overall methodological quality was high. Fixed-effects analysis showed that differences were not significant between the 2 groups in retear rate (RR, 0.94; 95% CI, 0.70 to 1.25; P = .66), Constant score (mean difference, 1.12; 95% CI, -1.38 to 3.61; P = .38), and University of California at Los Angeles (UCLA) score (mean difference, -0.68; 95% CI, -2.00 to 0.65; P = .32). The strength of GRADE evidence was categorized respectively as low for retear, moderate for Constant score, and low for UCLA shoulder score. CONCLUSIONS: Our meta-analysis does not support the use of platelet-rich plasma in the arthroscopic repair of full-thickness rotator cuff tears over repairs without platelet-rich plasma because of similar retear rates and clinical outcomes. LEVEL OF EVIDENCE: Level II, meta-analysis of Level I and II randomized controlled trials.

High activity of cubic PtRh alloys supported on graphene towards ethanol electrooxidation.

Cubic PtRh alloys supported on graphene (PtxRhy/GN) with different atomic ratio of Pt and Rh were directly synthesized for the first time using the modified polyol method with Br(-) for the shape-directing agents. The process didn't use surface-capping agents such as PVP that easily occupy the active sites of electrocatalysts and are difficult to remove. Graphene is the key factor for cubic shape besides Br(-) and keeping catalysts high-dispersed. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to characterize the structure and morphology of these electrocatalysts. The results showed that they were composed of homogeneous cubic PtRh alloys. Traditional electrochemical methods, such as cyclic voltammetry and chronoamperometry, were used to investigate the electrocatalytic properties of PtxRhy/GN towards ethanol electrooxidation. It can be seen that PtxRhy/GN with all atomic ratios exhibited high catalytic activity, and the most active one has a composition with Pt : Rh = 9 : 1 atomic ratio. Electrochemical in situ FTIR spectroscopy was used to evaluate the cleavage of C-C bond in ethanol at room temperature in acidic solutions, the results illustrated that Rh in an alloy can promote the split of C-C bond in ethanol, and the alloy catalyst with atomic ratio Pt : Rh = 1 : 1 showed obviously better performance for the C-C bond breaking in ethanol and higher selectivity for the enhanced activity of ethanol complete oxidation to CO2 than alloys with other ratios of Pt and Rh. The investigation indicates that high activity of PtxRhy/GN electrocatalyst towards ethanol oxidation is due to the specific shape of alloys and the synergistic effect of two metal elements as well as graphene support.

[Plasmacytoid urothelial carcinoma of the urinary bladder: a clinicopathologic study of 16 cases].

OBJECTIVE: To study the clinicopathologic features and prognosis of plasmacytoid urothelial carcinoma (PUC) of the urinary bladder. METHODS: The clinical and pathologic findings of 16 cases of PUC were retrospectively reviewed. Immunohistochemical study (MaxVision method) was carried out. The follow-up data were analyzed. RESULTS: There were altogether 15 males and 1 female. The age of patients ranged from 40 years to 85 years (median = 64 years). Most patients (15/16) presented with hematuria. The tumor cells were small to medium in size and contained eccentric nuclei and moderate to abundant eosinophilic cytoplasm, assuming a plasmacytoid appearance. The architectural pattern varied from loosely cohesive sheets to cords, papillae, small nests or gland-like structures. Most tumors invaded into the lamina propria or muscularis propria. Twelve of the 16 cases had concurrent conventional urothelial carcinoma component. Immunohistochemical study showed that the tumor cells in all cases were strongly positive for AE1/AE3, epithelial membrane antigen, CK7 and CK18. CK20 and uroplakin III were also expressed in 9 cases. CEA, p53, CD138, p63 and E-cadherin were positive in 12, 13, 15, 11 and 10 cases, respectively. Ki-67 index ranged from 5% to 70% (mean = 30%). All tumors were negative for vimentin, LCA, kappa/lambda light chains, S-100 protein, HMB 45,Melan A, smooth muscle actin and desmin. Follow-up information was available in 13 patients. The duration of follow up ranged from 3 months to 10 years. Three patients died of distant metastasis at 3, 27 and 60 months after the operation, respectively. One patient was alive with disease at 25 months. One was alive at 43 months with a prior recurrence. Another 8 patients were alive and disease free at 7 to 120 months. CONCLUSIONS: PUC of the urinary bladder is a rare variant of high-grade urothelial carcinoma. Immunohistochemical study with positivity for CK7, CK20, p63 and uroplakin III and negative staining for vimentin and LCA may be helpful in the differential diagnosis. PUC is a malignant tumor with high invasiveness, high recurrence rate and poor prognosis. Radical cystectomy is considered as the first line treatment for PUC.

[Chromophobe renal cell carcinoma: a clinicopathologic study and immunophenotypes of 42 cases].

OBJECTIVE: To study the clinicopathologic features, immunohistochemical profiles and prognosis of chromophobe renal cell carcinoma (ChRCC). METHODS: Forty-two cases of ChRCC were retrieved from the archival files of the Affiliated Hospital of Qingdao University, 401 Hospital of PLA and Qingdao Municipal Hospital from 2003 to 2011. The clinical and pathologic features of the tumors were reviewed. Hale colloidal iron staining was performed and EnVision immunohistochemistry was used to detect the expression of a series of immunologic markers. Forty cases of clear cell renal cell carcinoma and 10 cases of renal oncocytoma were selected as controls. RESULTS: The patients included 17 males and 25 females. The age of patients ranged from 39 years to 78 years (median age = 57 years). On gross examination, the tumors ranged from 2 cm to 19 cm in greatest dimension (mean size = 7.3 cm). Histologically, the tumors were mainly composed of solid sheets, acini or tubules of malignant cells. The tumor cells contained clear finely reticular ("chromophobe") and eosinophilic cytoplasm with perinuclear clearing. The nuclear outline was irregular and wrinkled. Nucleoli were inconspicuous and mitotic figures were barely seen. Hale colloidal iron stain was positive in all cases. Immunohistochemically, the tumor cells were variably positive for EMA (100%, 42/42), CK7 (95.2%, 40/42), Ksp-cad (92.9%, 39/42), CK18 (88.1%, 37/42), CD117 (61.9, 26/42), CD10 (31.0%, 13/42) and PAX2 (28.6%, 12/42). They were negative for vimentin, CA IX and TFE3. The follow-up period in 31 patients ranged from 2 to 77 months (average duration = 29 months). Three patients died of tumor metastasis 3, 8, 13 months respectively after the operation. Twenty-eight patients were still alive without evidence of tumor recurrence. CONCLUSIONS: ChRCC predominantly occurs in middle-aged and elderly patients. It often carries a favorable prognosis. The presence of plant cell-like morphology, pale cells with uniform reticular microvesicular appearance and perinuclear clearing are characteristic histologic features. The diffuse positivity for Hale colloidal iron stain and EMA/CK7/Ksp-cadherin/CD117-positive immunoprofiles are also useful in differential diagnosis.

[Effect of qindan fuzheng capsule on ultrastructure of microwave radiation injured cardiomyocytes and hepatocytes in rats].

OBJECTIVE: To explore effect of Qindan Fuzheng Capsule (QFC) on ultrastructure of cardiomyocytes and hepatocytes injured by high microwave radiation in rats. METHODS: Eighteen adult Wistar rats were equally divided into 3 groups in random: rats in Group A were untreated as the normal control, rats in Group B received 6 min microwave radiation (100 mW/cm2 high power) to cause injury of cardiomyocytes and hepatocytes, and Group C received the same radiation but treated with QFC perfusion, 2 mL (equivalent to 4.75 g crude drug) once a day, for 7 successive days, starting from 6 h after radiation. All rats were sacrificed 7 days later, their fresh tissue of heart apex and right lobe of liver were taken and prepared to routine transmission electron microscopy specimen for ultrastructural observation. RESULTS: Compared with Group A, different degrees of ultrastructural changes on nuclei and organelle were observed in Group B and C, but the injury in Group C was significantly milder than that in Group B, showing normal sized cells with good structure approximate to the morphology in Group A. CONCLUSIONS: QFC showed protective effect on microwave radiation injured ultrastructural changes in rats' cardiomyocytes and hepatocyte. Its mechanism was possibly correlated with the suppression of lipid peroxidation and the improvement of metabolism in myocardial and hepatic cells.

[Studies on the anomalous IR properties of CoPt nanorods].

One-dimensional CoPt nanorods were obtained through the galvanic displacement reaction and chemical reduction. The average diameter of the nanorods was measured to be about 166.3 nm and the length was mostly between 1.0 and 5.0 microm obtained from the scanning electron microscopy (SEM) measurement. The IR optical properties of the CoPt nanorods and bulk Pt were investigated by in situ FTIR reflection spectroscopy employing CO adsorption as probe reaction at the solid/gas interface. The results of in situ FTIR indicated that bulk Pt shows a normal IR optical property and the CoPt nanorods display abnormal infrared effects (AIREs). The authors can obtain the same results whether the CoPt nanorods were loaded on glassy carbon (GC) or Au substrates. These results demonstrated that the AIREs were generated mainly by CoPt nanorods and the influence of the substrate materials can be neglected. The study confirmed that one-dimensional CoPt nanorods show AIREs, and throw a new sense to comprehend the anomalous IR properties observed on low-dimensional nanomaterials.

Self-assembled copt nanoparticles monolayer film and its IR optical properties.

CoPt nanoparticles were prepared by galvanic displacement reaction, followed by a chemical reduction. The CoPt nanoparticles were spherical and the average diameter was about 33 nm obtained from the results of transmission electron microscopy (TEM), high resolution TEM and scanning electron microscopy (SEM). The results of powder X-ray diffration (XRD), energy dispersed X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) demonstrated that the surface of the product was mostly consist of Pt nanoparticles. An ordered monolayer film of CoPt nanoparticles on Si wafer was obtained by a Liquid/Liquid interface technique. In situ FTIR transmission spectral study indicates that the ordered self-assembled monolayer film of the CoPt nanoparticles shows Fano-like infrared effects, while the deposited CoPt nanoparticles exhibit normal enhanced IR adsorption. The results of the present paper demonstrated that the IR optical properties are closely related to the interactions and thickness of the nanomaterials and significant to understand the anomalous IR properties of nanometer materials.

Tuning the shape and catalytic activity of Fe nanocrystals from rhombic dodecahedra and tetragonal bipyramids to cubes by electrochemistry.

Fe nanocrystal catalysts were synthesized by electrochemistry. Shape transformations of Fe nanocrystals from rhombic dodecahedra and tetragonal bipyramids, both bounded by {110} facets, to 18-facet polyhedra enclosed by different combinations of {110} and {100} facets and finally to cubes exclusively covered by {100} facets have been achieved. A study of the surface-structure functionality of the Fe nanocrystals toward electroreduction of nitrite revealed that the electrocatalytic activity of the Fe nanocrystals increases as the fraction of {100} facets on the surface of the Fe NCs increases.

[Ethanol electrooxidation on carbon supported PtSn catalyst: in situ TRFTIR study].

Carbon supported PtSn catalyst (PtSn/C) was prepared by a modified polyol method and characterized by means of XRD. It was showed that the metal particle size was 2.2 nm and the unit cell parameter increased compared with Pt/C. In situ time-resolved Fourier transform infrared spectroscopy (TRFTIRS) was used to study the electrooxidation of ethanol on PtSn/C catalyst. COL was the main poison species adsorbed on the active sites to inhibit the further reaction of ethanol electrooxidation. Acetaldehyde and acetic acid were found to be the products of ethanol electrooxidation as competing reactions with ethanol dissociation when the potential was up to 0.3 V, which reduced the poisoning effect. The selectivity of acetic acid among the products was improved with the increase in the potential and reaction time. CO2, which appeared at 0.4 V, was the final product and yielded from the oxidation of COL. The catalytic mechanism of PtSn/C towards ethanol electrooxidation was analyzed based on the results.