A Deeper Understanding of H₂ Evolution Entirely from Water via Diborane Hydrolysis

Abstract

Hydrogen (H2) has drawn extensive attention due to its superior gravimetric capacity density and eco-friendly nature. Nowadays, hydrogen is mainly produced by the steam reforming of natural gas, a process that leads to massive emissions of greenhouse gases. Very recently, H2 evolution upon hydrolysis of diboranes (e.g., B2(OH)4 and B2pin2) is promising because both H atoms of the released H2 are obtained from water. This is different from the hydrolysis of sodium borohydride, dimethylaminoborane, ammonia borane, and tetramethyldisiloxane, where an H2 is generated with only one H atom from H2O and the other one from hydrogen storage materials. Importantly, diborane hydrolysis in D2O could provide an easy and simple method for D2 evolution. In this minireview, an overview of H2 evolution upon diborane hydrolysis with an extraordinary emphasis on the recent developments in mechanism study and applications is presented. The future research emphasis and perspectives of H2 evolution upon diborane hydrolysis have been suggested for commercialization as well.

Spatial Confinement of Pt Nanoparticles in Carbon Nanotubes for Efficient and Selective H2 Evolution from Methanol

“…This is a complete departure from the principles of the utilization of hydrogen energy. [22] Additionally, the large-scale industrial application of hydrogen is severely hampered by its safety issues as to storing and transportation, because of its extremely low density, super-high explosibility, and liquefaction Scheme 1. The synthesis of Pt/CNT.…”

“…This is a complete departure from the principles of the utilization of hydrogen energy. [ 22 ] Additionally, the large‐scale industrial application of hydrogen is severely hampered by its safety issues as to storing and transportation, because of its extremely low density, super‐high explosibility, and liquefaction dilemma. [ 23 ] Therefore, it still remains a severe challenge to develop hydrogen storage materials, including HCOOH, [ 24 , 25 , 26 , 27 ] hydrazine, [ 28 ] borohydrides [ 29 , 30 ] and alcohols, [ 31 ] for avoiding high cost and the safety risks in the production, storage, and transportation of hydrogen.…”

“…Therein, the optimal Pt/CNT nanocomposite presented the superior catalytic activity in H 2 evolution upon methanol dehydrogenation at the expense of B 2 (OH) 4 , with a TOF value of 299.51 min −1 at 30 °C. Among them, B 2 (OH) 4 was frequently applied in borylation reaction and reduction reaction, [ 22 ] and recently used as the sacrificial agent for H 2 production. [ 55 , 56 ] In order to speculate and verify its mechanism, the carrier effect, kinetic study, kinetic isotope effect, tandem reaction, and density functional theory (DFT) of H 2 production upon methanol dehydrogenation had been scrutinized in detail.…”

Transfer Hydrogenolysis of O‐ and N‐Benzyl Groups in Water with Tetrahydroxydiboron by Using an Amphiphilic Polymer‐Supported Nano‐Palladium Catalyst

“…Tetrahydroxydiboron [B 2 (OH) 4 ] has been gaining significant attention as a versatile reducing agent in organic synthesis. [5][6][7][8][9][10][11] Recently, we and other research groups have reported that B 2 (OH) 4 reduces various functional groups such as alkenes, alkynes, [7] heteroarenes, [7b,8] aryl halides, [7c] aryl ketones, [9] and nitroarenes [7d,8,10] in the presence of transition-metal catalysts. It has also been reported that the B 2 (OH) 4 -promoted reductions often proceed through transition-metal-catalyzed transfer hydrogenation from water under aqueous conditions.…”

“…It has also been reported that the B 2 (OH) 4 -promoted reductions often proceed through transition-metal-catalyzed transfer hydrogenation from water under aqueous conditions. [6] These findings prompted us to develop a catalytic debenzylation of Oand N-benzyl groups by B 2 (OH) 4 -mediated water-based transfer hydrogenolysis.…”