Adsorption of water at the SrO surface of ruthenates

Abstract

Although perovskite oxides hold promise in applications ranging from solid oxide fuel cells to catalysts, their surface chemistry is poorly understood at the molecular level. Here we follow the formation of the first monolayer of water at the (001) surfaces of Sr${}_{n+1}$Ru${}_n$O${}_{3n+1}$ ($n$ = 1, 2) using low-temperature scanning tunnelling microscopy, X-ray photoelectron spectroscopy, and density functional theory. These layered perovskites cleave between neighbouring SrO planes, yielding almost ideal, rocksalt-like surfaces. An adsorbed monomer dissociates and forms a pair of hydroxide ions. The OH stemming from the original molecule stays trapped at Sr-Sr bridge positions, circling the surface OH with a measured activation energy of 187 $\pm$ 10 meV. At higher coverage, dimers of dissociated water assemble into one-dimensional chains and form a percolating network where water adsorbs molecularly in the gaps. Our work shows the limitations of applying surface chemistry concepts derived for binary rocksalt oxides to perovskites.

References in corpus (4)

• Water adsorption and dissociation on SrTiO3(001) revisited: A density-functional theory study
• Surface and Bulk Structural Properties of Single Crystalline Sr3Ru2O7
• High chemical activity of a perovskite surface: reaction of CO with Sr${}_3$Ru${}_2$O${}_7$
• Point defects at cleaved Sr${}_{n+1}$Ru${}_n$O${}_{3n+1}$(001) surfaces

Cited by in corpus (5)

• Water Agglomerates on Fe3O4(001)
• Enhanced electrocatalytic activity via phase transitions in strongly correlated SrRuO3 thin films
• Probing Emergent Surface and Interfacial Properties in Complex Oxides via in situ X-ray Photoelectron Spectroscopy
• On the happiness of ferroelectric surfaces and its role in water dissociation: the example of bismuth ferrite
• Adsorption of CO on the Ca3Ru2O7(001) surface