DEVICE for

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DEVICE
for MEASURING DISSOLUTION of EVOLVED H2 in
the CATHODE METAL
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HADZI JORDANOV Svetomir, shj_at_ian.tmf.ukim.edu.mk

• FACULTY of
• TECHNOLOGY
• METALLURGY

UNIVERSITY Sts. CYRIL METHODIUS SKOPJE, R. of
MACEDONIA
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• Outlook
• Technique for measuring
  gas evolution rate -
  Modalities of application -
  Measuring dissolution of H2 in Me
• Dissolution of H2 in Ru and Pd
• C o n c l u s i o n s

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TECHNIQUE FOR MEASURING GAS EVOLUTION RATE

• H O W I T W O R K S ?
• 1. Gas is evolved in the main cell
• 2. Gas enters in bubble counting cell through a
  capillary immersed in solution
• 3. Gas is transformed into small bubbles of
  constant size

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How it counts bubbles?

• 4. Bubbles past trough the gap between 2 small
  electrodes and lower the current flowing between
  them (d.c. impulse)

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How it registers the bubbles?

• 5. X-t recorder registers the passage of each
  bubble

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O r

• 5. Counter (electronic device) registers the
  number of produced d.c. impulses ( number of
  bubbles)

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How it measures the gas rate?

• 6. With simple calibration the number of bubbles
  is transformed into the rate of gas evolution

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MEASURING GAS EVOLUTION RATE COUNTING
NUMBER OF GAS BUBBLES

• 1 bubble H2 0.007 ml
• 0.5 µg
• TECHNIQUE - simple
• - sensitive
• - reproducible 3

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MODALITIES OF APPLICATION

• Measuring of H2 evolution
  measuring of corrosion rate of base metals
• Measuring of H2 evolution characterization
  of inhibitors of corrosion
• Measuring of H2 coevolution determination
  of Current Efficiency (Zn
  electro-winning)
• Measuring of H2 evolution deficiency
  determination of H2 dissolution in metals

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EXAMPLES OF APPLICATION

• Corrosion rate of iron steel vs. pH

• C.E. of Zn electrowinning

Efficiency of inhibitor
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EXAMPLES OF APPLICATION

• Corrosion rate of iron steel vs. pH

Rate of corrosion of iron and some steels
in acids pH-dependence
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HYDROGEN IN METALS EXPERIMENTAL SET-UP

• 1. Steady state H2 at Pt cathode
  calibration of bubbling frequency
• 2. Switch from Pt to Me-cathode
  determination of H2 dissolution in
  tested Metal
• 3. Switch back to Pt cathode
  liberation of H2 kept in Me due to
  the cathode polarization (if any or if possible)

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HYDROGEN IN METALS D E T E R M I N A T I O N

• H2 in Ru

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HYDROGEN IN METALS D E T E R M I N A T I O N
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C O N C L U S I O N S

• Techniques main features
• Simple (home-made)
• Sensitive
• Reproducible
• Versatile

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More in - Bulletin of the Chemists and
Technologists of Macedonia, Vol.12, 3
(1993)- Chemical Instrumentation,
6 (2), 107 (1975)
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Aknowledgementthis presentation is part of
theINCO-COPERNICUS PROJECTacronymed
PROMETHEASPL ICA2-2002-10031(European
Commission)
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Prof. Svetomir Hadzi Jordanov, Ph.D
President of The Macedonian Chemical Soc.
B.Sc. 1964, Univ. Skopje M.Sc. 1969, Univ.
Belgrade Ph.D. 1973, Univ. Belgrade Postdoctoral
Studies, Univ. Otawa, Canada

• Research
• Electrocatalysis
• Electrocrystallization
• Corrosion Protection of Metals
• Environmental Issue

• Teaching
• Physical Chemistry
• Electrometallurgy
• Corrosion Protection
• of Metals