Manipulation of Hydrogen Binding Energy and Desorption Kinetics by Boron Doping of High Surface Area Carbon

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• 作者：Justin B. Bult ; Justin Lee ; Kevin O鈥橬eill ; Chaiwat Engtrakul ; Katherine E. Hurst ; Yufeng Zhao ; Lin J. Simpson ; Philip A. Parilla ; Thomas Gennett ; Jeffrey L. Blackburn
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：December 20, 2012
• 年：2012
• 卷：116
• 期：50
• 页码：26138-26143
• 全文大小：325K
• 年卷期：v.116,no.50(December 20, 2012)
• ISSN：1932-7455

文摘

Boron-doped high surface area carbon is shown to have unique chemical and structural properties that are advantageous for hydrogen storage. High surface area boron-doped carbon sorbents were produced by chemical vapor deposition of a boron-doped carbon (BC_X) layer onto CM-Tec activated carbon. Photoelectron spectroscopy indicates the incorporation of boron at levels up to 14.3 at. % into sites with varying bonding environments. High-resolution microscopy characterization demonstrates that the turbostratic boron鈥揷arbon layer has a c-plane spacing of 4.02 卤 0.24 脜, large enough to allow the diffusion of hydrogen intercalated between BC_X layers. Slower adsorption and desorption kinetics that depend sensitively on H₂ charging duration and temperature suggest the presence of hidden surface area of the turbostratic BC_X and enhanced binding energy sites. Our study suggests that the increased c-plane spacing, together with a significant concentration of electron-deficient sp² boron sites, combine to create a stronger H₂鈥搒orbent interaction than is typically achieved for undoped carbon sorbents.