Tailoring MgH_(2) for hydrogen storage through nanoengineering and catalysis

Hydrogen energy has been recognized as “Ultimate Power Source” in the 21st century, which could be the best solution to the looming energy crisis and climate degeneration in the near future. Due to its high safety, low price, abundant resources and decent hydrogen storage density, magnesium based solid-state hydrogen storage materials are becoming the leading candidate for onboard hydrogen storage. However,the high operation temperature and slow reaction rate of MgH_(2), as a result of the large formation enthalpy and high reaction activation energy,respectively, are the first and most difficult problems we need to face and overcome to realize its industrialization. Herein, a state-of-the-art review on tailoring the stable thermodynamics and sluggish kinetics of hydrogen storage in MgH_(2), particularly through nanoengnieering and catalysis is presented, aiming to provide references and solutions for its promotion and application. Promising methods to overcome the challenges faced by MgH_(2)/Mg, such as bidirectional catalysts and nanoconfinement with in-situ catalysis are compared and the required improvements are discussed to stimulate further discussions and ideas in the rational design of MgH_(2)/Mg systems with ability for hydrogen release/uptake at lower temperatures and cycle stability in the near future.

Effect of different additives on the properties of lithium alanate

LiAIH4 doped with Ni and Ce（SO4）2 additives and the effect of doping on temperature and hydrogen release were studied by pressure-content-temperature （PCT） experiment and X-ray diffraction （XRD） analysis. It is indicated that doping with Ni induces a significant decrease in temperature in the first step and LiA1H4 doped with 1mol% Ni presents the most absorption of hydrogen. Doping with Ce（S04）2 also causes a marked decrease, while the amount of hydrogen release changes only slightly. The results from X-ray diffraction analysis show that doping does not cause any structural change; Ni and Ce-containing phases are not observed at room temoerature or even at 250℃.

Hydrogen storage by liquid organic hydrogen carriers:Catalyst,renewable carrier,and technology--A review

Hydrogen has attracted widespread attention as a carbon-neutral energy source,but developing efficient and safe hydrogen storage technologies remains a huge challenge.Recently,liquid organic hydrogen carriers(LOHCs)technology has shown great potential for efficient and stable hydrogen storage and transport.This technology allows for safe and economical large-scale transoceanic transportation and long-cycle hydrogen storage.In particular,traditional organic hydrogen storage liquids are derived from nonrenewable fossil fuels through costly refining procedures,resulting in unavoidable environmental contamination.Biomass holds great promise for the preparation of LOHCs due to its unique carbon-balance properties and feasibility to manufacture aromatic and nitrogen-doped compounds.According to recent studies,almost 100%conversion and 92% yield of benzene could be obtained through advanced biomass conversion technologies,showing great potential in preparing biomass-based LOHCs.Overall,the present LOHCs systems and their unique applications are introduced in this review,and the technical paths are summarized.Furthermore,this paper provides an outlook on the future development of LOHCs technology,focusing on biomass-derived aromatic and N-doped compounds and their applications in hydrogen storage.

Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures

Decreasing hydrogen partial pressure can not only increase the activity of the hydrogen enzyme but also decrease the products inhibition, so it is an appropriate method to enhance the fermentative hydrogen production from anaerobic mixed culture. The effect ofbiogas release method on anaerobic fermentative hydrogen production in batch culture system was compared, i.e., Owen method with intermediately release, continuous releasing method, and continuous releasing ＋ CO2 absorbing. The experi- mental results showed that, at 35℃, initial pH 7.0 and glucose concentration of 10 g.L-1, the hydrogen produc- tion was only 28 mL when releasing gas by Owen method, while it increased two times when releasing the biogas continuously. The cumulative hydrogen production could reach 155 mL when carbon dioxide in the gas stream was continuously absorbed by 1 mol.L-1 NaOH. The results showed that acetate was dominated, accounting for 43% in the dissolved fermentation products in Owen method, whereas the butyrate predominated and reached 47%-53% of the total liquid end products when releasing gas continuously. It is concluded that the homoacetogenesis could be suppressed when absorbing CO2 in the gas phase in fermentative hydrogen production system.

Copper-Catalyzed Hydrogen Production through the Dehydrogenative Coupling of Methanol and Diamine

A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.