Effect of ultra-thin SnO2 coating on Pt catalyst for energy applications

Abstract

In this paper, we present a simple and novel approach for stabilizing a porous metal-based nanostructure through atomic layer deposition in which ultra-thin tin oxide (SnO 2 ) coats platinum (Pt) film. After heating the ultra-thin tin oxide-coated Pt samples at 300 o C and 500 o C and observing the in situ sheet resistance variations of Pt for 20 hours, we found that the ultra-thin tin oxide coating suppresses metal agglomeration. The thermal stability of ultra-thin tin oxide-coated Pt was greater than that of pure Pt, even at 300 o C and 500 o C. More interestingly, the ultra-thin tin oxide coating was found to maintain the morphology of its underlying porous Pt at test temperatures of 300 o C and 500 o C.

Review on process-microstructure-performance relationship in ALD-engineered SOFCs

“…Another type of ALD oxide, SnO 2 , was demonstrated as an overlayer for the Pt cathode; Chang et al investigated ALD SnO 2 coating on Pt for stabilizing a porous metal-based nanostructure. They observed the improvement in thermal stability, but not in cathodic activity, at 300-500°C [29].…”

“…Nanoporous structures of metals and ceramic, in combination with nanoparticles, are employed. However, the mechanical and chemical stability of electrode structures with high surface-to-volume ratio, especially nanostructures, may become a serious issue at elevated temperatures [27][28][29][30][31][32][33].…”

“…(1) ALD oxide on metallic cathode ALD oxide overlayers (or overcoatings, capping layers), e.g., MnO x [31], ZrO 2 [28], SnO 2 [29], doped ZrO 2 [30,32], CeO x [33], on metal cathodes have been actively researched in recent years [28][29][30][31][32] because they can compensate for the low thermal stability of porous metal electrodes, and in some cases, can also improve the ORR activity. While oxide overlayers can be fabricated by using other techniques (sputtering [136][137][138], infiltration [139][140][141]), the conformal nature of the ALD process may further help to enhance the stability of metallic electrodes.…”

Ridge‐Valley Nanostructured Samaria‐Doped Ceria Interlayer for Thermally Stable Cathode Interface in Low‐Temperature Solid Oxide Fuel Cell

“…One interesting way to enhance the thermal stability of noble metal electrodes for low‐temperature SOFCs is by the oxide overcoating method. Previous studies observed that a zirconia (ZrO 2 ), ceria (CeO 2 ), or tin oxide (SnO 2 ) capping layer formed using thin film deposition techniques, for example, sputtering, atomic layer deposition (ALD), on nano‐porous metal electrodes can protect the nano‐porous Pt cathode morphology from thermal agglomeration . Su et al showed that an ALD ZrO 2 over‐layer (1 nm) on a Pt electrode improved the lifetime of the electrode by nearly 70%.…”

Improving the thermal stability of nanoporous metal electrode thin films for low temperature solid oxide fuel cells

“…Reported methods to maintain the high density of nanoporous features of pure Pt electrode include electrode surface-capping by a thin layer of oxide, 44,46,57 employing the core-shell structure of the nanoparticles, 80 or alloying with another catalytically active element such as nickel 49 or ruthenium. 48 Pt.…”