Effects of calcination treatment on samples of mono-metallic Pd and Pd77-Ag23 alloy with primary particles around 8 nm were studied with the temperature-programmed reduction technique. Temperature profiles of hydrogen consumption for calcined samples from a stream of 10% H2 in N2 were monitored by a thermal conductivity detector. Two distinct peaks, i.e., a consumption of hydrogen for PdO reduction and a subsequent desorption of hydrogen from bulk palladium hydride, were observed. The extent of palladium oxidation upon calcinations increased with the temperature of calcination (To): i.e., chemisorption of oxygen on particle surface upon calcination at To < 373 K, reconstruction into a surface PdO structure at 473 K and incorporation into sublayers to form bulk PdO structure at high To. Minimum temperature (Tr) required for reduction of oxidized palladium by the hydrogen stream was generally low (150 K < Tr < 320 K) and increased with the extent of oxidation. A quantitative measurement of hydrogen desorbe...