Charge transfer at oxygen/zirconia interface at elevated temperatures: Part 10: Effect of platinum

Abstract

The effect of small Pt particles, present on the surface of yttria-stabilised zirconia (YSZ) (10 mol-%Y₂O₃), on charge transfer at the oxygen/zirconia interface has been studied using work function measurements in the range 873–1173 K. It was found that oxidation of the Pt–YSZ system in air results in the formation of a thin Y_aZr_bPt_cO_d type oxide layer that spreads over the surface of YSZ. The presence of Pt results in a lowering of the surface charge produced by oxygen chemisorption. A model describing the role of Pt and the Y_aZr_bPt_cO_d type oxide layer in the charge transfer at the triphase boundary formed of oxygen, Pt and YSZ is proposed.

Keywords:

• CHARGE TRANSFER
• OXYGEN CHEMISORPTION
• PLATINUM
• TRIPHASE BOUNDARY
• WORK FUNCTION
• YTTRIA-STABILISED ZIRCONIA