Protonic ceramic cells with thin BaZr0.8Y0.2O3-δ electrolytes for stable separation of H2 from H2-CO2 mixtures

Here we report selective separation of high-purity H-2 from a CO2-containing stream using protonic ceramic cells with thick Ni-BaZr0.1Ce0.7Y0.2O3-delta cathode substrates, thin BaZr0.8-Y0.2O3-delta electrolytes and thin Ni-BaZr0.8Y0.2O3-delta anodes, as fabricated by the tape casting and tape lamination methods. Scanning electron microscopy observations show an overall micron porous structure for both electrodes with some nano-scale porosities inside Ni particles. The measured H-2 flux out of 3%-humidified 10% H-2 -90% CO2 at 700 degrees C was 3.2 ml.cm(-2).min(-1) at 0.90 V with a Faraday's efficiency of 97.8%. A preliminary 50-hour measurement in 10% H-2 -90% CO2 shows a slight increase in the pumping voltage from 0.96 to 1.03 V with a constant H-2 flux of 6.5 ml.cm(-2).min(-1) and Faraday's efficiencies continuously above 97%, as enabled by excellent stability of BZY against CO2. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.