Proton conductivity in yttrium-doped barium cerate under nominally dry reducing conditions for application in chemical synthesis

Abstract

The applicability limits of BaCe0.9Y0.1O3−δ highlighted for use as a membrane in electrochemical reactors operating under nominally dry conditions.

Electrochemistry and energy conversion features of protonic ceramic cells with mixed ionic-electronic electrolytes

“…Although, the effect of this reaction on overall electron transport has been claimed to be negligible, 94 we note that hydrogen production in BaCeO 3 -based PCECs, hydrogen-permeable converters or hydrogen pumps should occur according to eqn (51):or2H + + 2e′ → H 2 Where e′ means external (for electrolytes) or internal (for MIECs) electron sources for the half-reaction.…”

“…Loureiro et al 94 estimated the equilibrium constant of reaction (49) to derive an empirical equation for BaCe 0.9 Y 0.1 O 3− δ : K red /(atm 1/2 ) = 2.54 × 10 21 exp(−9.68 × 10 4 T −1 ), whose high enthalpy (∼805 kJ mol −1 ) is responsible for the low reducibility of the studied phase at low- and intermediate-temperature ranges. In terms of partial conductivities, while the n-type electronic conductivity is 8 orders of magnitude lower than ionic conductivity at 400 °C, it is only 3 orders of magnitude lower at 600 °C (Fig.…”

Analysis of La4Ni3O10±δ-BaCe0.9Y0.1O3-δ Composite Cathodes for Proton Ceramic Fuel Cells

“…Hence, we aim to extend our previous work to assess the continued usability of the La 4 Ni 3 O 10±δ -BaCe 0.9 Y 0.1 O 3-δ composite cathodes for operation under such low humidity contents (i.e., p H2O ~10 −5 atm) [23,24]. Unfortunately, such conditions also lead to a severe increase in the electronic transport number of the electrolyte substrate [24], potentially erroneously decreasing the measured polarisation resistances [19,[25][26][27][28].…”

“…Despite this promise, the strong chemical interreaction of BCY10 with high levels of water vapour has been shown to severely compromise the long-term performance of this material [1,23]. To avoid this limitation, a very recent work highlighted the extended applicability of yttrium-doped barium cerate, BaCe 0.9 Y 0.1 O 3-δ (BCY10), for operation in nominally dry conditions in the intermediate temperature range (350-600 • C) [24].…”

“…In such conditions, this composition was shown to be able to retain predominant proton conduction to very low values of water vapour partial pressure (p H2O > 10 −4 -10 −5 atm). This feature is highly important as the chemical stability of this material can also be retained at such low water vapour partial pressures [23].…”