Platinum nanoparticle induced nanoionic effects on electrical conduction in strontium cerate and zirconate

Abstract

Heterointerfaces introduce unique localized defects into ionic conductors. This study explores the nanoionic characteristics exhibited by the proton-conducting oxides SrZr 0.9 Y 0.1 O 3-δ and SrCe 0.95 Yb 0.05 O 3-δ including finely dispersed precipitated platinum nanoparticles. The electrical conductivity of both the platinum-doped oxides revealed reversible nanoionic phenomena caused by the exsolution of the platinum in the form of platinum nanoparticles, at 0.5 vol% relative to the metal oxides, and dissolution in response to a change in gas atmosphere. In comparison with the original conductivity of SrZr 0.9 Y 0.1 O 3-δ and SrCe 0.95 Yb 0.05 O 3-δ , the conductivity of platinum-doped SrZr 0.9 Y 0.1 O 3-δ decreased significantly in a wet hydrogen atmosphere, whereas platinum-doped SrCe 0.95 Yb 0.05 O 3-δ showed almost no decrease in conductivity in the same atmosphere. The different responses of the two materials to the change in gas atmosphere are discussed in relation to the precipitation of platinum nanoparticles.

Tailored and Improved Protonic Conductivity through Ba(ZxCe10−x)0.08Y0.2O3−δ Ceramics Perovskites Type Oxides for Electrochemical Devices

“…Upon modifying the Zr ratio in SrZr 0.9− x Ce x Y 0.1 O 3−δ , Matsumoto et al., [29] however, observed a discontinuous change of conductivity with a maximum value (4.6×10 −3 S cm −1 at 600 °C) at the ratio of Zr to Ce of 5 : 4, even though the precise reason for the high conductivity is still elusive. In the quest to clarify the origin of the high conductivity in SrZr 0.5 Ce 0.4 Y 0.1 O 3−δ , the present authors and others [30–33] have systematically examined this composition to correlate electrical conductivity to the crystal structure and device performance.…”

Room temperature fabrication of highly proton conductive amorphous zirconia-based thin films achieved through precise nanostructure control

“…It has been reported that a decrease in ionic conductivity can be caused by the introduction of Pt nanoparticles to the electrolyte side at the vicinity of the proton-conducting oxide/Pt interface. 49,50 However, Pt diffusion into YSZ was unexpected in this study because all samples were fabricated under room temperature conditions. Therefore, we consider that Pt has little effect on ion transport properties.…”

Processing Ceramic Proton Conductor Membranes for Use in Steam Electrolysis

“…Powders of BaZr 0.44 Ce 0.36 Y 0.2 O 3−δ (BZCY(54) 8/9 2), SrZr 0.5 Ce 0.4 Y 0.1 O 3−δ (SZCY541), and Ba 0.5 La 0.5 CoO 3−δ (BLC) were synthesized by a modified wet solution route in house, using pre-determined concentrations of analytic grade metal nitrates [ 7 , 36 ]. Stoichiometric amounts of the following precursor’s Ba(NO 3 ) 2 (Wako, Osaka, Japan, 99.9%), ZrO(NO 3 ) 2 (Aldrich, Tokyo, Japan, 99%), Sr(NO 3 ) 2 (Soekawa Chemicals, Tokyo, Japan 99.9 %), Ce(NO 3 ) 3 ·6H 2 O (Kanto Chemical Co., Tokyo, Japan, INC 99.99%), Co(NO 3 ) 2 ·6H 2 O (Kanto Chemical Co., Tokyo, Japan, INC 99.95%), La(NO 3 ) 3 ·6H 2 O (Wako, city and country, 99.9%) and Y(NO 3 ) 3 ·6H 2 O (Mitsuwa’s Pure Chemicals, Osaka, Japan, 99.9 %) were dissolved in deionized water.…”