β(L)-Bi2Mo2O9: A new, highly active and selective, mild oxidation bismuth molybdate catalyst

A new bismuth molybdate, obtained by means of microwave-assisted hydrothermal synthesis, is described by the chemical formula: beta(L)-Bi2Mo2O9, in accordance with its low crystallization temperature and transition to beta-Bi2Mo2O9 at 532 degrees C. Its structure, solved ab initio using powder diffraction data, crystallizes in the monoclinic system (space group P2(1)/c), with a = 8.11413(5), b = 8.54445(5), c = 13.43623(6) angstrom, and beta = 123.5085(2)degrees. This phase has been tested as a catalyst for the oxidation of propene. It appears to be highly stable on stream, with a specific rate of propene conversion comparable to that of alpha-Bi2Mo3O12 and a slightly higher selectivity to acrolein. A possible active site for the abstraction of the first hydrogen from propene has been identified, by analogy with that proposed for alpha-Bi2Mo3O12 and seems to correspond to a molybdenyl Mo = O oxygen that is weakly coordinated to a neighboring Bi cation. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

The newly synthesized bismuth molybdate has shown potential catalytic properties for propene oxidation with good stability and slightly higher selectivity.