The thermochemic method, where the catalyst temperature is manipulated by Joule-heating, may falsify the underlying kinetics by inducing inhomogeneous solutions. This work analyzes the multiplicity and stability of these states in a wire with uniform activity with or without gaps in heat conduction. Measurements of integral properties may indicate the existence of inhomogeneities either by the existence of characteristic multiplicity patterns and bifurcation maps or by unique quantitative features. These tests are employed to show that the two intermediate branches, out of four observed in ammonia oxidation, are inhomogeneous solutions induced by lack of communication. The measured bifurcation set, separating the domains of existence of the four states, is mapped in the three dimensional soace of reactants concentrations and temoerature.
- Ammonia oxidation
- Steady state multiplicity