Enhanced hydrogenation characteristics of Li-Mg-N-H system catalyzed with TiO2 nanoparticles; a mechanistic approach. (7th December 2017)

• Record Type: Journal Article
• Authors: Shahi, Rohit R.; Mishra, Rajesh K.; Shukla, Vivek; Bhatnagar, Ashish; Srivastava, O.N.
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 49(2017)
• Page Start: 29350
• Page End: 29359
• Publication Date: 2017-12-07
• Subjects: Oxides -- Ball-milling -- XPS -- Chemisorptions -- Li-Mg-N-H -- Catalysts; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.09.174
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The report describes the effect of TiO2 nano particles on the hydrogenation characteristics of promising Li-Mg-N-H hydrogen storage system. The effect of different particle size of TiO2 (200, 25 and 7 nm) on de/re-hydrogenation characteristics of Mg(NH2 )2 /LiH mixture has been investigated. Desorption kinetics of Li-Mg-N-H system with 25 nm TiO2 gets enhanced upto ∼25% as compared to the pristine material kinetics at 453 K (180 °C). The report also deals mechanistic approach for hydrogen release from Li-Mg-N-H system in the presence of TiO2 nanoparticles through XPS analysis of catalyzed sample at various stages of reaction. The XPS analysis confirms that during dehydrogenation nitrogen atom present in Li-Mg-N-H system share their lone pair electrons to Ti (present in TiO2 ) and provides an alternate decomposition path which has lower activation energy for dehydrogenation. Highlights: TiO2 shows better catalytic effect as compared to Ti for Li-Mg-N-H system. The hydrogenation characteristics are improved appreciably in the presence of TiO2 nanoparticles. It is found that 25 nm possesses better catalytic effect as compared to 200 and 7 nm TiO2 . The XPS analysis confirms that during dehydrogenation N-atoms donate lone pair electrons to catalyst.