Hydrogen separation through tailored dual phase membranes with nominal composition BaCe0.8Eu0.2O3-δ:Ce0.8Y0.2O2-δ at intermediate temperatures.

Mariya E Ivanova,Wilhelm A Meulenberg,Maria Balaguer,Yoo Jung Sohn,Joachim Mayer,Justinas Palisaitis,Sonia Escolástico,Jose M Serra,Olivier Guillon

doi:10.1038/srep34773

Abstract

Hydrogen permeation membranes are a key element in improving the energy conversion efficiency and decreasing the greenhouse gas emissions from energy generation. The scientific community faces the challenge of identifying and optimizing stable and effective ceramic materials for H2 separation membranes at elevated temperature (400–800 °C) for industrial separations and intensified catalytic reactors. As such, composite materials with nominal composition BaCe0.8Eu0.2O3-δ:Ce0.8Y0.2O2-δ revealed unprecedented H2 permeation levels of 0.4 to 0.61 mL·min−1·cm−2 at 700 °C measured on 500 μm-thick-specimen. A detailed structural and phase study revealed single phase perovskite and fluorite starting materials synthesized via the conventional ceramic route. Strong tendency of Eu to migrate from the perovskite to the fluorite phase was observed at sintering temperature, leading to significant Eu depletion of the proton conducing BaCe0.8Eu0.2O3-δ phase. Composite microstructure was examined prior and after a variety of functional tests, including electrical conductivity, H2-permeation and stability in CO2 containing atmospheres at elevated temperatures, revealing stable material without morphological and structural changes, with segregation-free interfaces and no further diffusive effects between the constituting phases. In this context, dual phase material based on BaCe0.8Eu0.2O3-δ:Ce0.8Y0.2O2-δ represents a very promising candidate for H2 separating membrane in energy- and environmentally-related applications.

Highlights

Hydrogen permeation membranes are a key element to reach high energy conversion efficiency and decreasing the greenhouse gas emissions from power generation and energy-intensive industries, i.e. by capturing and utilizing CO2 or moving towards hydrogen-based systems by extracting highly pure H2 from gas mixtures[1,2,3]
Rietveld refinement on the X-ray diffraction (XRD) performed on the BCEO and CYO separately showed that the single phases were not formed after 6 h of calcination
Once the pressed pellet is sintered at 1600 °C, the observed splitting of peaks disappear and XRD reveals that a single BCEO perovskite phase and a single CYO fluorite were formed

Summary

Defective fuorite structured materials

La5.5WO11.25-δ La5.5W0.8Mo0.2O11.25-δ La5.5W0.8Re0.2O11.25-δ Nd5.5WO11.25-δ (Nd5/6La1/6)5.5WO12-δ (La5/6Nd1/6)5.5WO12-δ Nd5.5W0.5Mo0.5O11.25-δ Nd5.5W0.5Re0.5O11.25-δ wet 50% H2 in He – wet Ar wet 50% H2 in He – wet Ar wet 50% H2 in He – wet Ar wet 20% H2 in He – wet Ar wet 50% H2 in He – wet Ar wet 50% H2 in He – wet Ar wet 50% H2 in He – wet Ar wet 50% H2 in He – wet Ar

Perovskite structured materials

Results and Discussion

Conclusions

Author Contributions

Additional Information