Sterpenich Posted February 26, 2019 Share Posted February 26, 2019 Tracing a pe-Ph plot at 90°C I was wondering if there is no problem with the stability limit of water with Hydrogen. It not seem to be consistent with the database used. In my example, I used Thermoddem database from BRGM but when calculating the equation of the line, there is a mistake. In particular there seems to have a problem between the logK of the H2/H+ reaction and the equations which should be pe=-logK / 2 - pH for H2(g) = 2H+ + 2e- and for a H2 fugacity of one bar. However it seems to miss the minus of log K and the absolute value seems not to be the good one if you take an other database than the default one. When plotting a reaction path in this diagram where H2 and H2O co-exist, the dots do not follow the equilibrium line and are in the stability field of H2 which seems to confirm the problem. Thanks for your help Quote Link to comment Share on other sites More sharing options...
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