solid energetic materials, including aluminum (31 kJ g −1 ). [8][9][10] In medicine, boron neutron capture therapy, a noninvasive cancer treatment using boron-10, is another important application. [ 11 ] Furthermore, boron has the highest gravimetric hydrogen generation potential among inorganic solids that can be used for chemical splitting of water, up to 277 g H 2 per kg B. For comparison, silicon, aluminum, and sodium hydride have gravimetric hydrogen generation potentials of 142, 111, and 98 g H 2 kg −1 , respectively. Thus, boron is very interesting for on demand generation of hydrogen by reaction with water.Hydrogen is an emission-free fuel with high gravimetric energy content (120 kJ g −1 ) that can be used effi ciently in well-developed proton exchange membrane (PEM) fuel cells. Hydrogen generation and storage has attracted considerable attention in the past few years because of practical limitations of conventional gas storage methods, such as high-pressure tanks, for hydrogen. On-demand generation of hydrogen from water is one means of providing hydrogen for fuel cells and other uses. The direct thermolysis of water into hydrogen and oxygen requires temperatures above 2500 K and is therefore impractical in most applications. [ 12 ] Chemical water splitting, by reacting water with a metal to produce a metal oxide and release hydrogen, is an attractive means of splitting water at much lower temperature. However, the reaction rate of metal hydrolysis usually decreases with time because of oxide formation at the surface of the metal particles. Thermodynamically, boron has great potential for on-demand hydrogen generation by reaction with water. However, boron is generally nonreactive with water; it requires either a catalyst or very high temperature to react. Several studies of water splitting by reaction with boron, using steam at elevated temperatures, were published in the past few years. Kinetics of heterogeneous, noncatalytic hydrolysis of boron (micron sized, with average diameter near 44 µm) were investigated over a range of temperatures and steam concentrations, demonstrating increased reaction rate with increasing temperature (from 500 to 800 °C). [ 13 ] Although they did not explicitly report the total hydrogen produced in each experiment, this quantity can be estimated from their plots of hydrogen fl ow rate versus time. For example, 100 mg boron and 0.5 mL min −1 water fl ow generated ≈90 mL hydrogen gas in 12 min at 700 °C. In another study, amorphous boron hydrolysis at somewhat lower temperatures (below Boron nanoparticles (BNPs) are of great interest for applications such as neutron capture therapy of cancer cells, hydrogen generation from water, and high energy density fuels. Boron is particularly interesting for chemical water splitting, because of its high gravimetric hydrogen generation potential of 277 g H 2 per kg B. However, only a few studies of water splitting by reaction with boron are available, and those have used high temperature steam with external heating. Room-temperature bo...
Boron containing catalysts have great potential in the oxidative dehydrogenation of propane reaction. Herein, a series of 15, 25 and 42 at.% boron-hyperdoped silicon catalysts synthesized by laser pyrolysis were...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.