ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    A study of ethylamine at a gold rotating ring-disk electrode using pulsed electrochemical detection at the ring (1996)
    Weinheim : Wiley-Blackwell
    Electroanalysis 8 (1996), S. 726-731 
    Details
    ISSN: 1040-0397
    Keywords: Ethylamine ; Gold ; Voltammetry ; Adsorption ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Linear scan (cyclic) voltammetry at the disk with simultaneous pulsed electrochemical detection (PED) at the ring of a rotated ring-disk electrode (RRDE) is demonstrated to be applicable for studies of the complex anodic behavior of ethylamine at gold electrodes in 0.10 M NaOH. The oxidation of ethylamine at the disk occurs during positive scans concomitantly with formation of surface oxide (Au → AuOH → AuO). However, the final oxide-covered surface (AuO) is inert for further ethylamine oxidation. Data obtained at the RRDE demonstrate that the total ethylamine signal at the disk is composed of simultaneous contributions from: oxidative desorption of ethylamine preadsorbed at the oxide-free Au surface and oxidation of ethylamine transported to the disk simultaneously with oxide formation. Based on ring-disk data, preadsorbed ethylamine is estimated to correspond to a fractional surface coverage of 0.7 ± 0.1 monolayer for 10 to 60 μM ethylamine. Of this coverage, ca. 75% corresponds to ethylamine coadsorbed reversibly with OH- and 25% to ethylamine adsorbed irreversibly by a mechanism concluded to be chemisorption.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140080805
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Activation of titanium electrodes for voltammetric detection of oxygen and hydrogen peroxide in alkaline media (1997)
    Weinheim : Wiley-Blackwell
    Electroanalysis 9 (1997), S. 273-278 
    Details
    ISSN: 1040-0397
    Keywords: Titanium ; Voltammetry ; Oxygen ; Hydrogen peroxide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bright, freshly-polished Ti electrodes give minimal cathodic response for O2 and H2O2 in 1.0 M NaOH. However, the response is increased gradually by repeated application of a triangular waveform within the approximate potential limits of O2 response (ca. -1.5 to -0.7 V vs. SCE). This same voltammetric pretreatment applied for excessive periods results in formation of golden films on the Ti surfaces that are active for reduction of O2 and H2O2. Levich plots of cathodic current for O2 and H2O2 at rotated golden-Ti disk electrodes in 1.0 M NaOH (-1.35 V) are linear over a large range of rotational velocity (42 to 513 rad s-1), a behavior considered to be indicative of fast heterogeneous kinetics. Ring-disk data demonstrate that a small amount of H2O2 is produced throughout the potential region for O2 reduction and H2O2 is concluded to be an intermediate product in the O2-reduction mechanism. These observations are consistent with those reported previously for single-crystal TiO2 electrodes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140090402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Fast-pulsed amperometric detection at electrodes: A study of oxide formation and dissolution at platinum in 0.1 M NaOH (1994)
    Weinheim : Wiley-Blackwell
    Electroanalysis 6 (1994), S. 193-199 
    Details
    ISSN: 1040-0397
    Keywords: Platinum ; Platinum oxide ; Chronocoulometry ; Pulsed amperometric detection ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Results of a potential-step chronocoulometric study of oxide formation at a Pt-rotated minidisk electrode (0.00785 cm2) indicate that the anodic charge (qa) grows ca. as a linear function of the log time (t) for t = ca. 2-30 ms. Furthermore, the slope of the linear qa - log (t/ms) plot is proportional to the applied overpotential for oxide formation. The anodic peak current observed during linear potential-scan voltammetric experiments is nearly a linear function of scan rate (φ) for small φ (1000 〈 mV s-1) but shows substantial negative deviation from linearity for φ 〉 1000 mV s-1. The peak potential for oxide formation shifts in a positive direction for increasing values of φ, suggesting that this process is kinetically slow relative to large φ values. Reverse potential-step chronocoulometric measurements demonstrate that the background current in so-called “reverse-pulsed amperometric detection (RPAD)” can be decreased by inhibiting the conversion of the hydrous oxide (PtOH) to the inert oxide (PtO). Data also indicate that the rate of cathodic dissolution of surface oxide is dependent on applied potential for t 〈 2 to 30 ms. Oxide reduction continues even for t 〉 1000 ms.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140060304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Fast pulsed amperometric detection at noble metal electrodes: A study of oxide formation and dissolution kinetics at gold in 0.1 M NaOH (1992)
    Weinheim : Wiley-Blackwell
    Electroanalysis 4 (1992), S. 741-749 
    Details
    ISSN: 1040-0397
    Keywords: Chronocoulometry ; pulsed amperometric detection ; gold oxide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The anodic charge (qa) for oxide formation, obtained by potential-step chronocoulometry at a Au minidisk electrode, is nearly a linear function of log (t/ms) for t = ca. 3-30 ms with a slope proportional to the applied overpotential for oxide formation. It was demonstrated that, contrary to popular opinion based on voltammetric observation at slow scan rates (φ), the anodic current for oxide formation obtained using a linear potential-scan waveform is not a linear function of φ at large values of φ. It was also demonstrated that a reverse potential-step waveform can be used to interrupt the rapid oxide growth and, perhaps, inhibit the conversion of the hydrous oxide (AuOH) to the inert oxide (AuO). This result has probable significance for decreasing the background current during anodic pulsed amperometric detection of amines and sulfur compounds whose oxidation mechanisms are believed catalyzed by AuOH but not by AuO. The cathodic charge (qc) for oxide dissolution is approximately a linear function of t with a slope that is proportional to the applied potential.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140040802
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...