title: Synthesis of microporous boron-substituted carbon (b/c) materials using polymeric precursors for hydrogen physisorption.
abstract: This paper discusses a new synthesis route to prepare microporous boron substituted carbon (B/C) materials that show a significantly higher hydrogen binding energy and physisorption capacity, compared with the corresponding carbonaceous (C) materials. The chemistry involves a pyrolysis of the designed boron-containing polymeric precursors, which are the polyaddition and polycondensation adducts between BCl3 and phenylene diacetylene and lithiated phenylene diacetylene, respectively. During pyrolysis, most of the boron moieties were transformed into a B-substituted C structure, and the in situ formed LiCl byproduct created a microporous structure. The microporous B/C material with B content > 7% and surface area > 700 m2/g has been prepared, which shows a reversible hydrogen physisorption capacity of 0.6 and 3.2 wt % at 293 and 77 K, respectively, under 40 bar of hydrogen pressure. The physisorption results were further warranted by absorption isotherms indicating a binding energy of hydrogen molecules of approximately 11 kJ/mol, significantly higher than the 4 kJ/mol reported on most graphitic surfaces.
authors.affiliation: Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: T C Mike
authors.initials: TC
authors.lastname: Chung
authors.forename: Youmi
authors.initials: Y
authors.lastname: Jeong
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Alfred
authors.initials: A
authors.lastname: Kleinhammes
authors.forename: Yue
authors.initials: Y
authors.lastname: Wu