Hydrogen-related defects in titanium dioxide at the interface to palladium

Inserted hydrogen promotes oxidation catalysis of mixed Ru0.3Ti0.7O2 as exemplified with total propane oxidation and the HCl oxidation reaction

“…Recently, it was reported that a Pd layer supported on rutile-TiO 2 could accumulate a substantial amount of hydrogen at the interface (within a thickness of 2 nm). 19 In mixed oxide Ru 0.3 Ti 0.7 O 2 both worlds meet to the advantage. Ru is able to activate molecular hydrogen, while Ti is stabilizing the oxidation state of Ru against further reduction to metallic Ru.…”

“…At lower temperatures, hydrogen may form deep donors in rutile TiO 2 forming O–H + complexes, while in O vacancies hydrogen is stabilized as H − species; both species occur with low concentrations. 15–19…”

“…At lower temperatures, hydrogen may form deep donors in rutile TiO 2 forming O-H + complexes, while in O vacancies hydrogen is stabilized as H − species; both species occur with low concentrations. [15][16][17][18][19] One shortcoming of rutile-TiO 2 is the low activity towards molecular H 2 dissociation, requiring an active precious metal. Recently, it was reported that a Pd layer supported on rutile-TiO 2 could accumulate a substantial amount of hydrogen at the interface (within a thickness of 2 nm).…”

“…[10][11][12] Upon H 2 exposure at high temperatures (600-1000 °C), TiO 2 can be bulk-reduced to the Magneli phases down to Ti 2 O 3 . 13,14 At lower temperatures, theory 15,16 and experiments [17][18][19] indicate that traces of hydrogen can form deep donor levels in rutile TiO 2 forming O-H + complexes, while hydrogen in O vacancies can be stabilized as hydride H − species.…”