Metal

Materials science

Decomposition

Inorganic chemistry

Hydrogen

Organic chemistry

Thermal decomposition

Chemistry

The Journal of Physical Chemistry B

The decomposition of metal nitrates in air has been systematically studied by thermogravimetry. Observed temperatures of decomposition (Td) have been inversely correlated to the charge densities (CD) of the metal cations. Due to a back-donation of electronic cloud from the nitrate to an unfilled d-orbital of transition and noble metals, their nitrates generally exhibited lower Tds ( 850 K). The thermal stability/reducibility of metal nitrates in an hydrogen atmosphere has also been studied by temperature-programmed reduction (TPR). Observed reduction temperatures (Tr) for nitrates of the base metals and the noble metals are lower than their Td, i.e., Tr < Td. The lowering of Tr might be attributed to a spillover of hydrogen to a nitrate moiety through heterolytic (ionic) and homolytic (atomic) dissociation of hydrogen on the respective base and noble metals. The stoichiometry of hydrogen consumption, quantitatively measured from TPR, varied with the group of metal ca...

Thermal Decomposition of Metal Nitrates in Air and Hydrogen Environments