Atomic Force Microscopy Imaging of TiO2 Surfaces Active for C-C Bond Formation Reactions in Ultrahigh Vacuum

Interplay of support chemistry and reaction conditions on copper catalyzed methanol steam reforming

“…The low catalytic activity and poor stability and selectivity of Cu/TiO 2 anatase compared to rutile could be associated with the differences in the Lewis acidity of partially uncoordinated Ti 4+ cations, which in turn affects the interaction of polar molecules with the surface. 46 − 48 …”

“…At the same time, the CO 2 /CO ratio value was 7.40, which is significantly lower than that obtained on SiO 2 (231), Al 2 O 3 –SiO 2 (87), and TiO 2 rutile (47) catalysts. The low catalytic activity and poor stability and selectivity of Cu/TiO 2 anatase compared to rutile could be associated with the differences in the Lewis acidity of partially uncoordinated Ti 4+ cations, which in turn affects the interaction of polar molecules with the surface. − …”

Organic Reactions at Well-Defined Oxide Surfaces

“…AFM studies of reduced and various faceted, stoichiometric TiO 2 (001) surfaces have shown little difference between them at length scales >50 nm. 44 Finally, it should also be noted that there are at least two important issues in reactivity and catalysis by metal oxides where the still emerging field of oxide surface science has yet to rise to the challenge. The first is in the area of creating and characterizing the range of defects present on "real" oxide surfaces that may in fact dominate the chemistry of such materials.…”

“…Even changes detected by LEED and STM can be described in terms of alterations of local geometric structure, and do not necessarily propagate coherently over long (>20 nm) length scales. AFM studies of reduced and various faceted, stoichiometric TiO 2 (001) surfaces have shown little difference between them at length scales >50 nm …”

The Reactions of Model Metal Oxide Surfaces

“…Any of these processes produce oxygen anion vacancies, leaving electrons in the lattice, and reducing Ti 4+ cations to lower-oxidation state cations [39]. Re-annealing these reduced surfaces in the presence or absence of oxygen reoxidizes and reorders the near-surface region, and has been studied in some detail previously on the TiO 2 (001) surface [41][42][43][44]. Re-annealing these reduced surfaces in the presence or absence of oxygen reoxidizes and reorders the near-surface region, and has been studied in some detail previously on the TiO 2 (001) surface [41][42][43][44].…”