The enhanced hydrogen storage of micro-nanostructured hybrids of Mg(BH4)2-carbon nanotubes

A graphene-based material for green sustainable energy technology for hydrogen storage

The usage of graphene-based materials (GMs) as energy storage is incredibly popular. Significant obstacles now exist in the way of the generation, storage and consumption of sustainable energy. A primary focus in the work being done to advance environmentally friendly energy technology is the development of effective energy storage materials. Due to their distinct two-dimensional structure and intrinsic physical qualities like good electrical conductivity and wide area, graphene-based materials have a significant potential to be used in energy storage devices. Graphene and GMs have been employed extensively for this due to their special mechanical, thermal, catalytic and other functional qualities. In this review, we covered the topic of employing GMs to store hydrogen for green energy.

An Overview of the Recent Advances of Additive-Improved Mg(BH4)2 for Solid-State Hydrogen Storage Material

Recently, hydrogen (H2) has emerged as a superior energy carrier that has the potential to replace fossil fuel. However, storing H2 under safe and operable conditions is still a challenging process due to the current commercial method, i.e., H2 storage in a pressurised and liquified state, which requires extremely high pressure and extremely low temperature. To solve this problem, research on solid-state H2 storage materials is being actively conducted. Among the solid-state H2 storage materials, borohydride is a potential candidate for H2 storage owing to its high gravimetric capacity (majority borohydride materials release >10 wt% of H2). Mg(BH4)2, which is included in the borohydride family, shows promise as a good H2 storage material owing to its high gravimetric capacity (14.9 wt%). However, its practical application is hindered by high thermal decomposition temperature (above 300 °C), slow sorption kinetics and poor reversibility. Currently, the general research on the use of additives to enhance the H2 storage performance of Mg(BH4)2 is still under investigation. This article reviews the latest research on additive-enhanced Mg(BH4)2 and its impact on the H2 storage performance. The future prospect and challenges in the development of additive-enhanced Mg(BH4)2 are also discussed in this review paper. To the best of our knowledge, this is the first systematic review paper that focuses on the additive-enhanced Mg(BH4)2 for solid-state H2 storage.

Rhodium nanoparticles confined in titania nanotubes for efficient Hydrogen evolution from Ammonia Borane

Designing efficient catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) have attracted considerable attention. Rhodium (Rh) based catalysts with rational design present remarkable catalytic performance for the reaction. Herein, we report the confined Rh@TiO₂ catalysts synthesized by atomic layer deposition combining with the sacrificial template approach, in which the Rh nanoparticles are uniformly confined on the inner surface of the porous titania nanotubes. The optimized catalysts show high catalytic activity with a turnover frequency value of 334.1 mol_H2·mol_Rh^-1·min^-1 and better durability. Mechanistic investigation demonstrates that the cleavage of OH bands in water should be the rate determining step, and the appropriate concentration of NaOH can further enhance the hydrogen evolution activity. The catalysts can also achieve the hydrogenation of various organic substrates using AB as the hydrogen source. In addition, our present strategy is general and can be extended to the synthesis of other confined catalysts for various catalytic reactions.

Destabilization of Boron-Based Compounds for Hydrogen Storage in the Solid-State: Recent Advances

Boron-based materials have been widely studied for hydrogen storage applications. Examples of these compounds are borohydrides and boranes. However, all of these present some disadvantages that have hindered their potential application as hydrogen storage materials in the solid-state. Thus, different strategies have been developed to improve the dehydrogenation properties of these materials. The purpose of this review is to provide an overview of recent advances (for the period 2015–2021) in the destabilization strategies that have been considered for selected boron-based compounds. With this aim, we selected seven of the most investigated boron-based compounds for hydrogen storage applications: lithium borohydride, sodium borohydride, magnesium borohydride, calcium borohydride, ammonia borane, hydrazine borane and hydrazine bisborane. The destabilization strategies include the use of additives, the chemical modification and the nanosizing of these compounds. These approaches were analyzed for each one of the selected boron-based compounds and these are discussed in the present review.

Heterostructures Built in Metal Hydrides for Advanced Hydrogen Storage Reversibility

Hydrogen storage is a vital technology for developing on-board hydrogen fuel cells. While Mg(BH₄ )₂ is widely regarded as a promising hydrogen storage material owing to its extremely high gravimetric and volumetric capacity, its poor reversibility poses a major bottleneck inhibiting its practical applications. Herein, a facile strategy to effectively improve the reversible hydrogen storage performance of Mg(BH₄ )₂ via building heterostructures uniformly inside MgH₂ nanoparticles is reported. The in situ reaction between MgH₂ nanoparticles and B₂ H₆ not only forms homogeneous heterostructures with controllable particle size but also simultaneously decreases the particle size of the MgH₂ nanoparticles inside, which effectively reduces the kinetic barrier that inhibits the reversible hydrogen storage in both Mg(BH₄ )₂ and MgH₂ . More importantly, density functional theory coupled with ab initio molecular dynamics calculations clearly demonstrates that MgH₂ in this heterostructure can act as a hydrogen pump, which drastically changes the enthalpy for the initial formation of BH bonds by breaking stable BB bonds from endothermic to exothermic and hence thermodynamically improves the reversibility of Mg(BH₄ )₂ . It is believed that building heterostructures provides a window of opportunity for discovering high-performance hydrogen storage materials for on-board applications.

A review of transition-metal boride/phosphide-based materials for catalytic hydrogen generation from hydrolysis of boron-hydrides

Efficient hydrogen generation and storage is an essential prerequisite of a future hydrogen economy.

LiAlH4supported on TiO2/hierarchically porous carbon nanocomposites with enhanced hydrogen storage properties

LiAlH₄supported on TiO₂/hierarchically porous carbon (LAH–TiO₂/HPC) nanocomposites were prepared and they exhibited enhanced hydrogen storage performance.