The surface structure of the active bismuth molybdate catalyst

Roles of bulk γ(L)-Bi2MoO6 and surface β-Bi2Mo2O9 in the selective catalytic oxidation of C3H6

“…These results collectively suggest that the high selectivity for acrolein production in the oxidation of C 3 H 6 is a result of β-Bi 2 Mo 2 O 9 on the γ(L)-Bi 2 MoO 6 phase. Matsuura et al [3] have previously reported similar results. The XPS results in Table 3 shows that Mo/Bi ratios did not reach 1.0, which indicates that the surfaces were not completely covered with β-phase under these conditions.…”

“…The typical band at 1000 cm -1 for MoO 3 was not detected. The intensity of the band at 890 cm -1 increased when the excess of Mo was increased, up to an excess of 6 wt % MoO 3 . XPS results indicated that the Mo/Bi surface ratio ranged from 0.49 to 0.73when 0 to 6 wt% MoO 3 was added (Table 3).…”

“…However, the selectivity of pure γ(L)-Bi 2 MoO 6 (L=low temperature phase) remains an area of a debate. Matsuura et al [3] have previously reported that pure γ(L)-phase material displays poor activity and selectivity in the oxidation of butene.…”

The structure of γ-bismuth molybdate, Bi2MoO6, by powder neutron diffraction

“…Stoichiometric amounts of reagent grade (Baker) (NH4)6MOTO24 and Bi(NO3) 3 (in dilute HNO3) were simultaneously added to a beaker while the solution was rapidly stirred. Because the properties (and perhaps the structure) of Bi2MoO 6 are al.tered by minute changes in metal stoichiometry (Matsuura, Shuit & Hirakawa, 1980) the precipitate was not washed. The resultant slurry was stirred and heated to boiling until dry.…”

Synthesis and photoelectrochemical properties of thin bismuth molybdates film with various crystal phases

“…No noticeable change is observed in the samples treated at 400°C and 500°C. In deed, IR spectra reported in the literature for α, β, and γ phase display strong absorptions in the same frequency range [14]. Fig.…”