(52 bar) without cryogenic storage, is a reactant which can be used to generate electricity or propel a
spacecraft. It has been investigated as a cold gas propellant, monopropellant, and bipropellant; particularly
in the field of small satellites.[1,2] Nitrous oxide can also be used to generate electricity by acting as the
oxidizer in a fuel cell where N2O reduction occurs at the cathode and a fuel such as H2 is oxidized at the
anode.[3] Although the equilibrium potential in standard state aqueous electrolytes is 1.76 V vs SHE,
[3] large overpotentials in aqueous electrolytes make it difficult to efficiently extract power from this reaction. The
electrochemical reduction can be more readily achieved in a solid-oxide fuel cell (SOFC) with an oxygen
ion conductor for an electrolyte following the reactions in equations 1 and 2.[4] SOFCs also enable the use
of alternative fuels such as hydrocarbons, CO, and NH3. Additionally, the reaction product N2 is expected
to be usable as a cold gas propellant.
Cathode: 𝑁2𝑂 + 2𝑒− → 𝑁2 + 𝑂2− (1)
Anode: 𝐻2 + 𝑂2− → 𝐻2𝑂 + 2𝑒− (2)
We report on a SOFC device consisting of a Ni anode, a LaSrMnO3 cathode, and a Sc-doped ZrO2
electrolyte substrate. The maximum operating power which can be extracted from this system using N2O
as an oxidizer and H2 as a fuel, the conversion efficiency of N2O to N2, and a comparison of the performance
of N2O with air and O2 are all evaluated under a range of operating temperatures and flow rates.
References
1. V. Zakirov, M. Sweeting, T. Lawrence, and J. Sellers, Acta Astronautica., 48, 353–362 (2001).
2. V. Tarantini, B. Risi, R. Spina, N. G. Orr, and R. E. Zee, in Small Satellites Systems and Services
Symposium, p. 1–12 (2016).
3. A. Aziznia, A. Bonakdarpour, E. L. Gyenge, and C. W. Oloman, Electrochim. Acta, 56, 5238–5244
(2011).
4. T. Li, M. F. Rabuni, L. Kleiminger, G. H. Kelsall, U. W. Hartley, K. Lim, Energy Environ. Sci., 9, 3682–3686 (2016).