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Hydrogen Release and Uptake of MgH 2 Modified by Ti 3 CN MXene.
- Source :
- Inorganics; Jun2023, Vol. 11 Issue 6, p243, 11p
- Publication Year :
- 2023
-
Abstract
- MgH<subscript>2</subscript> has a high hydrogen content of 7.6 wt% and possesses good reversibility under normal conditions. However, pristine MgH<subscript>2</subscript> requires a high temperature above 300 °C to release hydrogen, with very slow kinetics. In this work, we utilized Ti<subscript>3</subscript>CN MXene to reduce the operating temperature and enhance the kinetics of MgH<subscript>2</subscript>. The initial temperature of MgH<subscript>2</subscript> decomposition can be lowered from 322 °C for pristine MgH<subscript>2</subscript> to 214 °C through the employment of Ti<subscript>3</subscript>CN. The desorbed MgH<subscript>2</subscript> + 7.5 wt% Ti<subscript>3</subscript>CN can start absorption at room temperature, while the desorbed pristine MgH<subscript>2</subscript> can only start absorption at 120 °C. The employment of Ti<subscript>3</subscript>CN can significantly improve the hydrogen release kinetics of MgH<subscript>2</subscript>, with the desorption activation energy decreasing from 121 to 80 kJ mol<superscript>−1</superscript>. Regarding thermodynamics, the desorption enthalpy changes of MgH<subscript>2</subscript> and MgH<subscript>2</subscript> + 7.5 wt% Ti<subscript>3</subscript>CN were 79.3 and 78.8 kJ mol<superscript>−1</superscript>, respectively. This indicates that the employment of Ti<subscript>3</subscript>CN does not alter the thermal stability of MgH<subscript>2</subscript>. Phase evolution studies through the use of X-ray diffraction and electron diffraction both confirm that Ti<subscript>3</subscript>CN remains stable during the hydrogen release and uptake process of the composite. This work will help understand the impact of a transition metal carbonitride on the hydrogen storage of MgH<subscript>2</subscript>. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 23046740
- Volume :
- 11
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Inorganics
- Publication Type :
- Academic Journal
- Accession number :
- 164648700
- Full Text :
- https://doi.org/10.3390/inorganics11060243