Abstract: The interaction and non-crystalline spontaneous dispersion at the interface of five systems of transition metal
binary oxide, namely, TiO₂(anatase)-MoO₃, MoO₃-V₂O₅, Fe₂O₃-MoO₃, WO₃-MoO₃ and ZrO₂-MoO₃ containing 0～100wt% MoO₃ respectively,
were characterized by XRD, BET, FT-IR. The five systems were prepared by dry mixing and grinding up at room temperature, and then calcining at appropriate
temperatures below melting point of two component oxides(500℃/5h). XRD quantitative analysis and extrapolation of crystal phase content indicate
that each component oxide disperses spontaneously to form a non-crystalline phase at interface, and has a dispersed threshold value (the maximum dispersion
capacity). BET measurements show the specific surface area of all samples are much smaller(3.71～11.3m²/g) than that of the supports such as γ-Al₂O₃ SiO₂ and TiO₂ gel etc. The dispersed threshold
values of MoO₂ (0.33～1.43g·10^-2cm^-2 determined by XRD and BET in the present paper are far greater than the monolayer dispersion capacity of MoO₃
(0.117g·10^-2cm^-2) calculated from TANG’s model of O^2- close-packed monolayer dispersion and also larger than MoO₃ monolayer dispersion capacity(0.169g·10^-2cm^-2)
calculated from the spherical octahedron model suggested in our ensuing paper. Such larger dispersed threshold value in the much smaller specific surface area
signifies non-monolayer dispersion and/or chemical reaction at interface. By means of FT-IR spectra and its differential spectra, the new species of
non-crystalline phase at interface and its characteristic absorption bands are discovered for the first time, and these bands are correlated to molecular
structure, such as IR characteristic absorption bands of non-crystalline phase MoO₃ appear at 960 and 826～828 cm^-1.

Key words: interface structure of binary transition metal oxides, non-crystalline phase interface and its dispersed threshold value, bulk crystal residual ratio, characterizations （XRD, BET and FT-IR）