High Temperature Chemistry of Complex Vaporization/Decomposition Processes: Final Report, September 1977-August 1988.

摘要

This research generated a series of systematic studies of the high temperature vaporization/decomposition behavior of a number of metal sulfates and chromates. A clearer picture is now beginning to emerge regarding the kinetic features of sulfate decompositions, and of the many ways that retardation of the SO3 yields SO2 conversion step affects these processes. The degree to which this step is coupled to the initial lattice SO4(-2) decomposition is a critical feature, and the action of certain metal and oxide catalysts for the SO3 conversion has given varied results that appear to be strongly temperature dependent. For the alkali sulfates and chromates, which undergo both decomposition and molecular vaporization, these studies yield the first quantitative measure of the relative contributions of these two processes, as well as accurate thermodynamic data for the M2SO4 and M2CrO4 gaseous species. Derived vapor entropies were especially useful in checking the validity of various spectroscopic and molecular constant assignments for the M2SO4 and M2CrO4 species. Overall, the results of this research yield a self-consistent base of information that significantly improves our understanding of the high temperature chemistry of these complex and interesting inorganic compounds. 9 refs.