CHEMICAL ETCHING OF MOLYBDENUM TRIOXIDE - A NEW TAILOR-MADE SYNTHESISOF MOO3 CATALYSTS

Crystalline catalysts of orthorhombic MoO3 have been prepared via a va por phase deposition method, and their crystallographic structure has been affirmed by XRD and FTIR investigations. A chemical etching metho d has been developed for restructuring these thermally processed catal ysts. Using a 0.1 M NaOH etchant, {001} and {100} plane areas of the c atalysts can be significantly increased while surface steps, ledges, a nd terraces are created. Moreover, alternate crystal plane combination s of either {100} and {010} or the {001} and {010} are observed on cry stal edges and rectangular etch pits in the basal planes {010}. Both m aterials chemistry of MoO3 and etching mechanisms have been studied on the basis of the surface morphological evolution of etching patterns of the catalysts. Technological merits and the processing parameters o f this new method have also been identified. Following the findings of the current work, it is believed that the chemically carved surface s tructures may be crucial for certain MoO3-involving catalytic reaction s.