Effects of Rare Earth Dopants on Crystal Structures of Bismuth Molybdate Catalysts
Crystal structures of Bi2Mo3O12 and Bi1.8Ln0.2Mo3O12 (Ln = Ce, Nd, Dy, Er) were studied using Rietveld structural refinements of X-ray powder diffraction data. Substitution of 10 mol% Ln for Bi produced changes in lattice parameters, bond lengths and distances between metal ions. These changes such as decreases in average bond lengths of Mo1O4 tetrahedra and variations in the distances between adjacent metal ions on the same plane could be ascribed to different ionic radii and electronegativty of Bi and rare earth atoms, and might be related to catalytic activity of bismuth molybdate for the selective oxidation and ammoxidation of alkenes.
Pengcheng Wang, Liqun Ai, Yungang Li, Xiaoming Sang and Jinglong Bu
Y. Z. Cheng et al., "Effects of Rare Earth Dopants on Crystal Structures of Bismuth Molybdate Catalysts", Advanced Materials Research, Vols. 295-297, pp. 1046-1049, 2011