Ne. Fouad et al., THERMOANALYTICAL RESOLUTION OF HYDROGEN-INFLUENCED REDUCTIVE EVENTS IN THE DECOMPOSITION COURSE OF AMMONIUM PARATUNGSTATE, Thermochimica acta, 239, 1994, pp. 137-145
Hydrogen-influenced reductive events in the decomposition course of am
monium paratungstate (APT) were resolved by thermal analysis (TG and D
TA) as a function of the heating atmosphere (air, N2 and H-2) and rate
(2-20-degrees-C min-1). A kinetic characterization of the events was
carried out non-isothermally. The results indicated that the reductive
events begin after the complete decomposition of APT into WO3 near 40
0-degrees-C, and lead eventually to the formation of W0 at 700-800-deg
rees-C. Thus, it was concluded that a pre-calcination of APT-containin
g materials might develop upon reduction to monolayer-type W0 catalyst
s.