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Abstract:
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The electron donating properties of La2O3 activated at 300, 500 and 800·C and its mixed oxides with
alumina are reported from the studies on adsorption of electron acceptors of varying electron affinity on
La203. The electron acceptors with their electron affinity values given in parenthesis are:
7,7,8,8-tetracyanoquinodimethane (2.84 eV), 2,3,5,6-tetrachloro-I,4-benzoquinone (2.40 eV) and
p-dinitrobenzene(l.77eV). The basicity of the oxide has been determined by titration with n-butylamine and
Ho.max values are reported. The limit of electron transfer from the oxide to the electron acceptor is between
2.40 and 1.77 eV. It is observed that La203 promotes the surface electron properties of alumina without
changing its limit of electron transfer. |