EXPERIMENTAL-STUDY OF BIFURCATION DIAGRAMS AND MAPS OF 2 PARALLEL INTERACTING CATALYTIC REACTIONS

Steady state multiplicity features of systems in which two reactions occur simultaneously may be affected by thermal and kinetic interactions and be qualitatively different from those of a single reaction. This is illustrated by an experimental study of the catalytic co-oxidation of hydrogen with either ammonia, butane or ethylene on a Pt wire. The bifurcation diagrams of wire temperature at a fixed hydrogen concentration vs. co-reactant concentration reveal multiplicity features which cannot be accounted for just by thermal interaction. The ignited branch was discontinuous at intermediate H//2 concentrations and extinction occurred upon increasing the co-reactant concentration. The loci of the observed ignition and extinction points were used to construct a bifurcation map in the concentration plane. The maps show that kinetic inhibition exists between the two reactions in addition to thermal interaction.