Copper oxide supported on alumina III. X-ray K-absorption edge studies of the Cu2+ species

Investigation of Combined S02/N0x Removal by Ceria Sorbents

“…This study is in agreement with that of Lo Jacono and Schiavello (1976) who observed no crystalline CuO or CuA1,04 for copper loadings up to 10 percent. It also confirms the study of Selwood and Dallas (1 948) who showed that the magnetic susceptibility of supported CuO is about twenty times that of unsupported CuO for copper loadings less than 11 percent, a result later attributed to effects of the aluminate surface phase (Wolberg and Roth, 1969).…”

Investigation of combined S02/N0x Removal by Ceria Sorbents

“…This study is in agreement with that of Lo Jacono and Schiavello (1976) who observed no crystalline CuO or CuA1,04 for copper loadings up to 10 percent. It also confirms the study of Selwood and Dallas (1 948) who showed that the magnetic susceptibility of supported CuO is about twenty times that of unsupported CuO for copper loadings less than 11 percent, a result later attributed to effects of the aluminate surface phase (Wolberg and Roth, 1969). 988) studied properties of CuO/A1,03 adsorbent for SO,.…”

Combined DeSOx/DeNOx reactions on a copper on alumina sorbent-catalyst. 1. Mechanism of sulfur dioxide oxidation-adsorption

“…It should be noted that the alumina support stabilizes well-dispersed copper ions up to nearly monolayer coverage, probaby in the form of a surface spinel according to literature data on copper on alumina systems (Lo Jacono et al, 1982;Strohmeier et al, 1985;Wolberg and Roth, 1969), whereas for higher loadings, amorphous CuO microparticles also form. The analysis of the change in the specific rate of S02 removal per copper atom (Figure 5) suggests that CuO microparticles are less active in the DeSO* reaction due to the formation of a first surface sulfated layer which inhibits the further reaction of subsurface layers.…”

“…On the contrary, for both A1203 and Ti02 supports the surface area has a pronounced influence on the DeSO* activity, even for values of the surface area higher than those required for the formation of a copper oxide monolayer and thus for a complete hypothetical dispersion of copper ions. In fact, it is known (Friedman et al, 1978;Marion et al, 1990;Lo Jacono et al, 1982; Strohmeier et al, 1985;Wolberg and Roth, 1969) that for a loading of copper oxide on alumina of about 5% and a surface area of around 100 m2/g the copper ions are well dispersed, with predominantly tetragonally distorted octahedal environments and the absence of Cu-O-Cu bonds. For higher loadings, microcrystalline copper oxide appears to be present.…”