The stoichiometry for hydrogen titration of oxygen on supported platinum

A reinvestigation of the reaction between hydrogen and oxygen chemisorbed on supported platinum has established the following stoichiometry for conditions of 25 °C and pressures above about 10 torr: Pt (surface) + 12O2(g) → PtO (surface) With unsupported platinum, a different stoichiometry for the hydrogen titration prevails, namely, Use has been made of the revised stoichiometry for supported platinum in determining the dispersion of platinum on alumina and platinum on silica. A new flow method for routinely performing the hydrogen titration of chemisorbed oxygen is described. Results by this method compare favorably with those obtained with a more precise (but more tedious) static method.