While analyzing the FTIR spectra of my catalyst material for ORR activity in fuel cell, I got some adsorption bands intensities at 3300/cm which are lower in one sample then other. According to literature, these intensities are related to O-H stretching vibrations. These results combine with other bands favors the presence of free water content in catalyst structure. So my question is that what is the effect of presence of free water content on orr activity?
Thank you in advance .
Could be bound or hydrogen-bonded water to the surface, which is normal. There are several steps involved in ORR, and protons are needed. Perhaps the bound waters are more acidic than bulk water and act as the proton in PCET during ORR?
Thank you Kyle A. Grice and Artur Braun I believe it has positive effect on ORR in alkaline media as we need water to react with Oxygen.