2228.     MCCARTNEY, J. T., SELIGMAN, B., HALL, W. K., AND ANDERSON, R. B.  Electron Microscopic Study of Metal Oxides and Metal Oxide Catalysts.  Jour. Phys. and Colloid Chem., vol. 54, 1950, pp. 505-519; Chem. Abs., vol. 44, 1950, p. 5691.

        Changes in structure of Fe₂O₃ gel, hydrous NiO, CuO powder, Ag₂O powder, CoO powder, Co basic carbonate, Co-ThO₂-MgO (100:6:12) catalyst, Co-kieselguhr (100:200) catalyst, Co-ThO₂-MgO-kieselguhr (100:6:12:200) catalyst, and Fe₂O₃ catalyst (Fe:Cu:K₂CO₃, 100:10:0.5) on reduction were studied by determination of weight losses and comparisons of electron micrographs and surface areas by N₂ adsorption.  Surface areas determined from particle sizes from micrographs and by adsorption permit estimating porosity.  The individual differences in structure and changes on reduction are described.  Precipitated oxides and catalysts always showed decrease in surface area on reduction, and a sizable portion of this decrease occurred in reduction rather than by sintering.  Decrease in sintering on reduction of Co basic carbonate is effected by the addition of promoters and kieselguhr, the order of increasing effectiveness being kieselguhr<ThO₂, MgO<ThO₂+MgO.  Electron micrographs are useful but difficult to interpret unless combined with the surface-area determinations by gas adsorption.

        MCDONALD, H. J.  See abs. 3158.

        MCGEE, J. P.  See abs. 768, 3100.

        MCKEEVER, C. H.  See abs. 3670.