Experimental Comparison of Hydrogen Peroxide Catalysts for a Hydrogen

This paper presents an experimental comparison of the catalytic activity of different alumina-based catalysts for highly concentrated hydrogen peroxide (85% w.) decomposition. Three pellet-shaped catalysts with manganese oxide or platinum active phases were considered. Their performances were investigated by measuring the temperature increase in the catalytic bed after several injections of 100 μL of hydrogen peroxide in a constant-volume chamber. This setup evidenced a loss of reactivity after several injections, which was due to water poisoning. Pellets were, then, tested in a small-scale catalytic chamber plugged into a combustor. Hydrogen peroxide was injected at various mass flow rates (from 4.5 to 9.0 g⋅s−1) through the catalytic chamber. The temperature evolution at the exhaust was recorded via a thin thermocouple (1 mm) and used to compare the activity of the different catalysts. The specific surface area, the active phase amount, and the platinum dispersion were measured after the tests. Catalysts experienced a decrease of those values, evidencing the ageing of the catalytic material. Preliminary combustion tests were performed for all catalysts in a hydrogen peroxide/n-decane bipropellant combustor. Results were compared to evaluate the influence of the efficiency of the catalytic system on combustion performance.