Improved hydrogen sorption kinetics in Mg modified by chosen catalysts

Significance 

The development of low carbon emission technologies has been favored by the increasing mitigation measures against the use of fossil fuels. This has also compelled serious development of renewable energy sources as an alternative to fossil fuels. Among the available renewable energy sources, hydrogen energy has particularly shown the potential of substituting fossil fuels for various applications due to its efficiency and relatively high energy density. However, storage of hydrogen has remained a challenge in the realization of its full potential. Therefore, researchers have been looking for alternative hydrogen storage methods and have identified the use of magnesium-based alloy materials as a promising candidate for effective hydrogen storage.

This can be attributed to the excellent cycling behavior and high hydrogen storage capacity of the MgH2 hydride phase. However, the high operating temperature due to the high thermodynamic stability is a great threat to its efficiency. Therefore, decreasing the stability of MgH2 is highly desirable.

Recent studies have shown that decreasing the stability of MgH2 is quite expensive and difficult. Alternatively, other considerations such as the use of dual tuned plasma materials are equally unfavorable for enhancing the equilibrium hydrogen pressure. Currently, hydrogen sorption kinetics in magnesium-based hydrogen storage materials has been considered an effective alternative solution. As such, favorable mechanisms have also been initiated to improve hydrogen sorption kinetics in magnesium.

To this note, Academy of Sciences of the Czech Republic scientists: Dr. Jiri Cermak, Dr. Lubomir Kral, and Dr. Pavla Roupcova looked at the feasibility of several chosen additives as excellent catalysts for hydrogen sorption kinetics. In particular, five different types of additives were tested and the results obtained for each individual additive compared to that in the existing literature. Their main objective was to determine a composition that could be used to improve the hydrogen storage kinetics of magnesium.

The authors commenced their research work by modifying magnesium using ten different catalysts and then investigated the hydrogen sorption characteristics of a combination of the additives together with a ball-milled blend of magnesium. Amorphous carbon was used as an anti-sticking agent to enhance the accuracy of the obtained results. The effect of every additive on the sorption kinetics was determined by setting the concentration of both the additive and the amorphous carbon at approximately 12wt %.

The experimental results showed that NaCl, Mg2Si and LiF mixtures increased the hydrogen equilibrium pressure and decreased desorption time. At the same time, NaCl and LiF were responsible for shifting the peak temperature to the lowest peak temperature at a temperature of 623K. In summary, Dr. Jiri Cermak and his colleagues successfully demonstrated the effective ways for improving hydrogen sorption kinetics in magnesium by using additives. This will, therefore, advance hydrogen storage for future utilization of hydrogen energy in both mobile and distributed systems as an alternative to fossil fuels. Their work is currently published in International Journal of Hydrogen Energy.

Improved hydrogen sorption kinetics in Mg modified by chosen catalysts - Advances in Engineering Improved hydrogen sorption kinetics in Mg modified by chosen catalysts - Advances in Engineering Improved hydrogen sorption kinetics in Mg modified by chosen catalysts - Advances in Engineering

About the author

Jiri Cermak (researcher ID G-1541-2014) from Institute of Physics of Materials, Academy of Sciences of the Czech Republic and CEITEC- Central European Institute of Technology IPM AS CR, Brno, Czech Republic, obtained his magister degree (Dr.) at University of Jan Evangelista Purkyne, Brno Czech Republic (now Masaryk University, Brno) in 1977. His professional specialization is solid state physics, now with the focus on materials physics.

He obtained his Doctor of Technical Sciences degree (DSc.) in 2005. In the first period of his career he studied prevailingly diffusion in defected solids, low-temperature diffusion and diffusion along high-diffusivity paths. In the last years he has studied mainly hydrogen storage in solids. He was twice at long-term scientific stays in Germany (Alexander von Humboldt Stiftung 1987-1988 and 1989-1991 at Institut fuer Metallforschung Muenster). He was awarded two times by the Award of the Academy of Sciences of the Czech Republic (2006 as a member of the research team; Surfaces and Interfaces in Construction Materials – Application of Modern Technologies and Computer Simulation and 2009 as a leader of the team; Hydrogen storage).

About the author

Lubomir Kral (researcher ID A-7313-2009) from Institute of Physics of Materials, Academy of Sciences of the Czech Republic graduated at Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, University of Technology Brno, Czech Republic in 2002 (Dipl. Eng.). He gained his Ph.D. grade at IPM AS CR Brno in 2007. He devoted himself professionally to mutual diffusion and thermodynamics in welded joints of steels and, in last years, he takes part in research of hydrogen storage in solids and partly also in projects focused to Mechanisms of plastic deformation and twinning interfaces in hexagonal metals. He was at long-term scientific stay in Germany (Alexander von Humboldt Stiftung 2005 at Institut fuer Metallforschung Muenster). He was awarded by the Award of the Academy of Sciences of the Czech Republic (in 2009 as a member of the team; Hydrogen storage). He gained an extensive experience in EM.

About the author

Pavla Roupcova (researcher ID-8788-2012) from Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, University of Technology Brno, Czech Republic and from CEITEC-Brno University of Technology, Brno, Czech Republic, graduated at Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, University of Technology Brno, Czech Republic in 2002 (Dipl. Eng.). She gained his Ph.D. grade at IPM AS CR Brno in 2007.

She takes part in investigation of electrical, magnetic and transport properties of amorphous and nano-sized metallic materials. As for experimental techniques, X-ray diffraction is her principal tool of structural and phase analyses, where she achieved an excellent professional level. This is why she is sought after as a member of diverse research projects that involve structural analyses. She is a co-author of numerous studies on hydrogen interaction with solid matter.

Reference

Cermak, J., Kral, L., & Roupcova, P. (2019). Improved hydrogen sorption kinetics in Mg modified by chosen catalysts. International Journal of Hydrogen Energy, 44(16), 8315-8324.

Go To International Journal of Hydrogen Energy

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