Platinum (Pt) particles with high thermal durability are required for ceramic electrodes. In this work, spherical Pt particles coated with Al2O3 were prepared by coating pure Pt particles with Aluminum (Al) chelate followed by heat-treatment at 700°C. The thermal-gravimetric analysis of pure Pt particles and coated Pt particles showed that the weight decrease of coated particles is small compared to pure Pt particles. Thermal durability of an electrode made from the Pt particles was measured by repeating heat-treatment at 1500°C. The rate of change in the electrical resistance of an electrode prepared from Al-coated Pt particles was lower than that of the electrode prepared from pure Pt particles.
