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

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Loureiro, FJA (Author) Other; Perez Coll, D (Author) Other; Graca, VCD (Author) Other; Mikhalev, SM (Author) Other; Ribeiro, AFG (Author) Other; Adélio Mendes (Author) FEUP; Fagg, DP (Author) Other

Journal

Title: Journal of Materials Chemistry A

Vol. 7

ISSN: 2050-7488

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00Q-XTN

DOI: 10.1039/c9ta04584h

Abstract (EN): Electrochemical membrane reactors using proton-conducting ceramics are promising and efficient technologies for the production of valuable chemical products by the promotion of hydrogenation/dehydrogenation reactions. Due to a very high equilibrium constant for hydration, yttrium-doped barium cerate, BaCe0.9Y0.1O3-delta (BCY10), presents one of the highest proton conductivities at low temperatures among known proton-conducting ceramic oxides (e.g. similar to 10(-3) S cm(-1) at 400 degrees C under humidified atmospheres, p(H2)O similar to 10(-2) atm). Nonetheless, BCY10 is commonly discarded for such applications due to its poor chemical stability towards hydroxide or carbonate formation. Moreover, the use of humidified atmospheres may not be feasible for many chemical syntheses, due to undesired side reactions. The current work, therefore, combines impedance spectroscopy, thermogravimetric analysis, coulometric titration and defect chemistry modelling to assess the limits for pure protonic conductivity in BCY10 in nominally dry atmospheres (p(H2)O similar to 10(-4) to 10(-5) atm, at low temperatures <600 degrees C), conditions where its stability and applicability to industrially relevant chemical synthesis reactions may be maintained, whilst still being hydrated. This work, thereby, unlocks a new application area for proton-conducting ceramics in a wide range of hydrogenation/de-hydrogenation reactions in the nominal absence of water.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8