Oxidation of hydrogen on WC at low temperature

✍ Scribed by S. Bodoardo; A.M. Maja; A.N. Penazzi; F.E.G. Henn

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 635 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00434-3

✦ Synopsis

The chemical reaction between hydrogen and oxygen on dry WC has been studied by measuring the pressure decay of various gaseous mixtures in a sealed glass reactor. At the beginning of the tests, the P&/P"% ratio in the mixture ranged between 6:l and 1:6 and the total pressure was almost always 1 atm. Electrochemical oxidation of hydrogen has been investigated measuring the anodic current of WC pellets maintained at various potentials.

In a first approximation the results suggest that the rate of chemical oxidation of hydrogen is proportional to Pt+ only. The deviation from the expected behaviour, increasing with the P",,/P"o, ratio, can be attributed to local temperature enhancement on the reaction sites or to an effect of the P"a,/P"o, ratio on the number of active centres. A slight influence of oxygen at low pO,,/pOoZ ratios has been detected.

The effect of WC on electrochemical oxidation of hydrogen increases with the applied potential and is proportional to the specific BET area of the catalyst. The tests on the PbOz-WC couple indicate that it is possible to put WC in contact with the positive active mass of the Pb-acid battery without marked undesirable effects.