The present study replicates a 1D, steady, chemically-reacting, reduced-order model for hydrogen peroxide flow through a monopropellant catalyst bed as described in Pasini et al. [9] with model validation completed by comparison with both model data and experimental data from Jung et al. [10]. Adaptations were made to improve heat transfer capabilities within the model and to adapt the model such that a hydroxylammonium nitrate and water mixture could be used as the propellant. Polynomial chaos expansion was implemented to decrease sampling time in order to perform non-deterministic analyses including: quantification of global sensitivities using Sobol indices, construction of axial property profiles with uncertainty envelopes for random physical inputs, and construction of posterior probability distributions with confidence intervals for variation in chemical tuning parameters. Results from the study show that model behavior is primarily governed by propellant mass fraction and activation energy of the global reaction. Additionally, posterior distributions indicate that activation energy and number of active sites per volume are related by a logarithmic family of solutions as a result of the reaction advancement gradient form in the model.