Catalytic Rate Dependence on UWr and

A general observation which has emerged from electrochemical promotion studies is that over wide ranges of catalyst work function D (0.2 - 1.0 eV) catalytic rates depend exponentially on catalyst work function O  

Typical examples of electrophobic reactions are shown on Fig. 4.28 for the catalytic oxidation ofC2H4 and ofCH4 on Pt/YSZ. As also shown in this figure, increasing also causes a linear variation in activation energy Ea  

Electrophilic reactions also frequently conform to Eq. (4.49) with a 0. An example is shown in Fig. 4.29 for the case of C2H4 oxidation on Pt supported on CaIno.iZro.903.a, a H+ conductor. At a first glance it is surprising that the 

Actually, as shown in Fig. 4.30, C2H4 oxidation on Pt/Na3Zr2Si2POi2, where Na3Zr2Si2POi2 (NASICON) is a Na+ conductor, can exhibit volcano-type behaviour, i.e. electrophobic behaviour at low potentials followed by electrophilic behaviour at higher potentials. 

The transition from volcano-type behaviour to electrophobic behaviour upon changing p02 is shown in Fig. 4.31 for the case of CO oxidation on Pt/p -Al203. Another example of volcano-type behaviour is shown in Fig. 4.32 for the case of NO reduction by C3H6 on Pt/ 3 -Al203.98,99 

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