Hydrides

Abstract

The article contains sections titled: 1. Introduction 2. Hydrides of the Alkali and Alkaline Earth Metals 2.1. General 2.2. Lithium Hydride 2.3. Sodium Hydride 2.4. Potassium Hydride 2.5. Beryllium Hydride 2.6. Magnesium Hydride 2.7. Calcium Hydride 3. Binary and Complex Hydrides of the Boron Group 3.1. General 3.2. Lithium Tetrahydridoborate 3.3. Lithium Triethylhydridoborate 3.3. Lithium Tri-sec-butylhydridoborate 3.4. Sodium Tetrahydridoborate 3.5. Sodium Cyanotrihydridoborate 3.6. Potassium Tetrahydridoborate 3.7. Aluminum Hydride 3.8. Lithium Tetrahydridoaluminate 3.9. Lithium (tri-tert-butoxy)hydrido-aluminate 3.10. Sodium Tetrahydridoaluminate 3.11. Sodium bis(2-methoxyethoxy)dihydridoaluminate 3.12. Diisobutylaluminum Hydride 4. Hydrides of the Transition Metals 4.1. Binary Hydrides 4.1.1. Titanium Hydride 4.1.2. Zirconium Hydride 4.2. Intermetallic Hydrides 4.3. Complex Hydrides of Transition Metals 4.3.1. Di(η5-cyclopentadienyl)chlorohydridozirconium(IV) 4.3.2. Carbonylhydrido-tris(triphenylphosphine)rhodium(I) 5. Use of complex hydrides for organic synthesis 5.1. Overview 5.2. Chemoselective Reductions 5.3. Enantioselective Reductions 6. Use of metal hydrides for energy storage 6.1. Hydrogen Storage 6.1.1. Reversible Hydrogen storage 6.1.2. Non-reversible Hydrogen storage 6.2. Thermochemical applications 6.3. Battery applications 7. Handling, Storage, and Transportation 8. Toxicology and Occupational Healt

Advances in catalysing the hydrogen storage in main group metals and their tetrahydroborates and tetrahydroaluminates

“…Their stability in air increases as the ionic character of the salt increases, namely increasing stability from Li toward K and from Mg to Ca. 149 KBH 4 is stable in dry air and not hygroscopic. NaBH 4 is stable in dry air and can be stored in an airtight container for a long time.…”

“…Mg is produced on a large scale in the smelting industry (1 million tonnes in 2024) 148 and can be hydrogenated directly in a rotary autoclave at 300–400 °C and 100–150 bar hydrogen pressure, or in THF solvent at 60–70 °C and 80 bar in the presence of catalysts. 149 A major disadvantage is its sensitivity to oxygen and water, with Mg nanopowders reacting violently with air and presenting the hazard of dust explosions. 150 Pure and finely divided MgH 2 is also pyrophoric.…”

“…AlH 3 is currently not produced in industry; the main small scale laboratory production methods are based on the reaction of LiAlH 4 with AlCl 3 in a diethylether solvent (Scheme 1). 149,151 The energy intensive nature of the desolvation process and conversion of the LiCl by-product to lithium limits the potential of this method for large scale production. An alternative to this synthetic route could be the thermal decomposition of Al(Et) 3 (triethylaluminium), produced on an industrial scale from Al, H 2 and ethylene in a two-step process; 152 however, the current synthesis at the laboratory scale is still suffering from low yields (19%).…”

“…, from NaH and B(OCH 3 ) 3 . 149 All other tetrahydroborates can be synthesized by metathesis reaction from NaBH 4 (Scheme 2). 149,211–215…”

Advances in catalysing the hydrogen storage in main group metals and their tetrahydroborates and tetrahydroaluminates

“…Their stability in air increases as the ionic character of the salt increases, namely increasing stability from Li toward K and from Mg to Ca. 149 KBH 4 is stable in dry air and not hygroscopic. NaBH 4 is stable in dry air and can be stored in an airtight container for a long time.…”

“…Mg is produced on a large scale in the smelting industry (1 million tonnes in 2024) 148 and can be hydrogenated directly in a rotary autoclave at 300–400 °C and 100–150 bar hydrogen pressure, or in THF solvent at 60–70 °C and 80 bar in the presence of catalysts. 149 A major disadvantage is its sensitivity to oxygen and water, with Mg nanopowders reacting violently with air and presenting the hazard of dust explosions. 150 Pure and finely divided MgH 2 is also pyrophoric.…”

“…AlH 3 is currently not produced in industry; the main small scale laboratory production methods are based on the reaction of LiAlH 4 with AlCl 3 in a diethylether solvent (Scheme 1). 149,151 The energy intensive nature of the desolvation process and conversion of the LiCl by-product to lithium limits the potential of this method for large scale production. An alternative to this synthetic route could be the thermal decomposition of Al(Et) 3 (triethylaluminium), produced on an industrial scale from Al, H 2 and ethylene in a two-step process; 152 however, the current synthesis at the laboratory scale is still suffering from low yields (19%).…”

“…, from NaH and B(OCH 3 ) 3 . 149 All other tetrahydroborates can be synthesized by metathesis reaction from NaBH 4 (Scheme 2). 149,211–215…”

Properties of Negatively Charged Ruthenium Clusters in Molten Sodium Chloride

“…Na 3 N is thermally unstable, whereas Li 3 N is thermally stable . The same holds for NaH and LiH, which would be important if hydrogen is included in the attempt to form ammonia. Ammonia synthesis would of course require molten salt eutectic mixtures with lower melting point than NaCl (1074 K).…”

Advances in catalysing the hydrogen storage in main group metals and their tetrahydroborates and tetrahydroaluminates

“…Their stability in air increases as the ionic character of the salt increases, namely increasing stability from Li toward K and from Mg to Ca. 149 KBH 4 is stable in dry air and not hygroscopic. NaBH 4 is stable in dry air and can be stored in an airtight container for a long time.…”

“…Mg is produced on a large scale in the smelting industry (1 million tonnes in 2024) 148 and can be hydrogenated directly in a rotary autoclave at 300–400 °C and 100–150 bar hydrogen pressure, or in THF solvent at 60–70 °C and 80 bar in the presence of catalysts. 149 A major disadvantage is its sensitivity to oxygen and water, with Mg nanopowders reacting violently with air and presenting the hazard of dust explosions. 150 Pure and finely divided MgH 2 is also pyrophoric.…”

“…AlH 3 is currently not produced in industry; the main small scale laboratory production methods are based on the reaction of LiAlH 4 with AlCl 3 in a diethylether solvent (Scheme 1). 149,151 The energy intensive nature of the desolvation process and conversion of the LiCl by-product to lithium limits the potential of this method for large scale production. An alternative to this synthetic route could be the thermal decomposition of Al(Et) 3 (triethylaluminium), produced on an industrial scale from Al, H 2 and ethylene in a two-step process; 152 however, the current synthesis at the laboratory scale is still suffering from low yields (19%).…”

“…, from NaH and B(OCH 3 ) 3 . 149 All other tetrahydroborates can be synthesized by metathesis reaction from NaBH 4 (Scheme 2). 149,211–215…”

Properties of Negatively Charged Ruthenium Clusters in Molten Sodium Chloride

“…Na 3 N is thermally unstable, whereas Li 3 N is thermally stable . The same holds for NaH and LiH, which would be important if hydrogen is included in the attempt to form ammonia. Ammonia synthesis would of course require molten salt eutectic mixtures with lower melting point than NaCl (1074 K).…”

Advances in catalysing the hydrogen storage in main group metals and their tetrahydroborates and tetrahydroaluminates

“…Their stability in air increases as the ionic character of the salt increases, namely increasing stability from Li toward K and from Mg to Ca. 149 KBH 4 is stable in dry air and not hygroscopic. NaBH 4 is stable in dry air and can be stored in an airtight container for a long time.…”

“…Mg is produced on a large scale in the smelting industry (1 million tonnes in 2024) 148 and can be hydrogenated directly in a rotary autoclave at 300–400 °C and 100–150 bar hydrogen pressure, or in THF solvent at 60–70 °C and 80 bar in the presence of catalysts. 149 A major disadvantage is its sensitivity to oxygen and water, with Mg nanopowders reacting violently with air and presenting the hazard of dust explosions. 150 Pure and finely divided MgH 2 is also pyrophoric.…”

“…AlH 3 is currently not produced in industry; the main small scale laboratory production methods are based on the reaction of LiAlH 4 with AlCl 3 in a diethylether solvent (Scheme 1). 149,151 The energy intensive nature of the desolvation process and conversion of the LiCl by-product to lithium limits the potential of this method for large scale production. An alternative to this synthetic route could be the thermal decomposition of Al(Et) 3 (triethylaluminium), produced on an industrial scale from Al, H 2 and ethylene in a two-step process; 152 however, the current synthesis at the laboratory scale is still suffering from low yields (19%).…”

“…, from NaH and B(OCH 3 ) 3 . 149 All other tetrahydroborates can be synthesized by metathesis reaction from NaBH 4 (Scheme 2). 149,211–215…”

Properties of Negatively Charged Ruthenium Clusters in Molten Sodium Chloride

“…Na 3 N is thermally unstable, whereas Li 3 N is thermally stable . The same holds for NaH and LiH, which would be important if hydrogen is included in the attempt to form ammonia. Ammonia synthesis would of course require molten salt eutectic mixtures with lower melting point than NaCl (1074 K).…”