The Structure of Active Centers in Nickel Catalyst. Ii.

Multilayer Oxide Films on Anodized Platinum

“…This again assumes the oxidizability to be caused by mechanical strain in the electrode surface but supposes this strain to arise during the reduction of the phase oxide rather than during its formation. The electrodeposition of metals is known to give catalytically active layers rich in both dislocations and point defects (43). Moreover, Piercy (44) has demonstrated that Pt can be loaded with a type of defect which anneals out at room temperature at rates not incompatible with the data of Fig.…”

Mechanochemical Methods

“…A close correlation between the nature and the concentration of lattice defects and the specific catalytic activity has been found [29][30][31][32][33], and consequently defects such as dislocations [21,23,30,[34][35][36][37], planes of crystallographic shear [34,38], and steps in the facets [39] are assumed to be catalytically active sites. However, according to Molchanov and Buyanov [13,40], only a few studies [23,41] have provided direct experimental evidence for the role of well-defined defects in the increase in the catalytic activity and allowed a description of the structure of active sites at the atomic level.…”

“…These groups demonstrated increases in the catalytic activities of Cu [21,30], Ni [35,36], Ag [37], Au [93], and Pt [94] in a series of reactions such as the decomposition of diazonium chloride, the dehydrogenation and oxidation of ethanol, the hydrogenation of cinnamic acid, and the decomposition of formic acid. These groups demonstrated increases in the catalytic activities of Cu [21,30], Ni [35,36], Ag [37], Au [93], and Pt [94] in a series of reactions such as the decomposition of diazonium chloride, the dehydrogenation and oxidation of ethanol, the hydrogenation of cinnamic acid, and the decomposition of formic acid.…”

Observation of Active Areas in Thin Films of Palladium

“…Active centers in catalysts have been attributed by other investigators to emergent dislocations (1,2), and point defects (2). Other kinds of crystal imperfections may also function as active centers, such as stacking faults, sessile dislocations, and impurity atoms.…”