Study of Reaction Mechanism in Solution Combustion Synthesis of Transition Metals

In this paper, we investigate the reaction mechanism followed during the solution combustion synthesis of transition metals (Cu, Ni and Co). Metal nitrates were mixed with a choice of fuel (glycine, and urea) and dissolved in deionized water to get a homogeneous solution with uniform properties. This solution is heated over a hot plate heater to initiate the highly exothermic combustion reaction resulting in the synthesis of metals/metal-oxides. Theoretical models describing combustion synthesis and thermodynamic calculations were used as guiding tools to predict the expected outcomes and to modify the experimental parameters leading to desired phase (metal/metal-oxide) synthesis. TGA-DTA analysis of the reactants (metal-nitrates and fuel) along with FTIR analysis of gases released during decomposition of reactants at various temperatures helped us in developing a consistent mechanism to describe the steps followed during combustion synthesis. These materials are currently being used as catalysts and their catalytic properties will also be discussed in the paper.