Beyond Hydrogen Storage: Metal Hydrides for Catalysis

Abstract

Metal hydrides (MHs) are featured for their reversible hydrogen absorption and desorption properties, which are conventionally used as hydrogen storage materials. MHs can also be used for catalysis, particularly for chemical reactions that involve hydrogen. This Review summarizes the historical and recent progress in the catalytic application of MHs. The focus topic is how the reversible hydrogen absorption and desorption properties of MHs enable their catalytic effect in hydrogen involving chemical reactions. We start with the basic properties of MHs, and their applications in hydrogen storage and related fields. The application of MHs in four important catalytic reactions: olefin hydrogenation, reversible hydrogen storage in liquid organic hydrogen carriers, CO2 hydrogenation, and NH3 synthesis are discussed. Finally, we compare MH-based catalysts with their analogues, including hydrogen spillover, oxyhydrides, mixed-anion hydrides, and electrides in catalysis. The Review demonstrates the inherent relationship between MH catalysis and their intrinsic hydrogen absorption and desorption properties, providing insights into diverse applications of MHs beyond hydrogen storage.

Pt/CB-Catalyzed Chemoselective Hydrogenation Using in situ-Generated Hydrogen by Microwave Mediated Dehydrogenation of Methylcyclohexane under Continuous-Flow Conditions

“…However, large-scale storage, transportation, and handling of molecular hydrogen are challenging, not only because of regulatory restrictions on highly flammable and explosive gases but also due to the need for control based on physical properties such as specific gravity, boiling point, and boil-off, as well as infrastructure development and other cost issues [11][12][13][14][15][16][17][18]. In response to these challenges, chemically stable substances known as liquid organic chemical hydrides (LOCH) have received much attention [13,[19][20][21][22][23][24]. Methylcyclohexane (MCH) is a type of LOHC that can store more than 500 times its own volume of H₂ gas and can be transported via pipelines, tankers, and road tankers, which are part of the fossil fuel infrastructure [25][26][27][28].…”

Properties of Ti-Based Hydrogen Storage Alloy

“…hydrides [11] [12] [13], porous materials [14] [15] [16], etc. At present, only hydrogen storage alloys [17] have been applied in practice on a large scale.…”

Pt/CB-Catalyzed Chemoselective Hydrogenation Using In Situ-Generated Hydrogen by Microwave-Mediated Dehydrogenation of Methylcyclohexane under Continuous-Flow Conditions

“…However, large-scale storage, transportation, and handling of molecular hydrogen are challenging, not only because of regulatory restrictions on highly flammable and explosive gases but also due to the need for control based on physical properties such as specific gravity, boiling point, and boil-off, as well as to infrastructure development costs and other cost issues [11][12][13][14][15][16][17][18]. In response to these challenges, chemically stable substances known as liquid organic chemical hydrides (LOCHs) have received much attention [13,[19][20][21][22][23][24]. Methylcyclohexane (MCH) is a type of LOHC that can store more than 500 times its own volume of H 2 gas and can be transported via pipelines, tankers, and road tankers, which are part of fossil fuel infrastructure [25][26][27][28].…”