title: Facile solid-phase synthesis of the diammoniate of diborane and its thermal decomposition behavior.
abstract: The recent mechanistic finding of the hydrogen release pathways from ammonia borane (AB) has sparked new interest in the chemistry and properties of the diammoniate of diborane (DADB), an ionic isomer of AB. We herein report a facile one-step solid-phase synthesis route of DADB using inexpensive starting materials. Our study found that mechanically milling a 1 : 1 NaBH(4)/NH(4)F powder mixture causes the formation of crystalline DADB via a NH(4)BH(4) intermediate. The produced DADB can be readily separated from the sodium fluoride (NaF) by-product by a purification procedure using liquid ammonia at -78 °C. The thermal decomposition behavior of DADB was studied using synchronous thermal analyses, particularly in comparison with AB. It was found that the decomposition steps and products of DADB are similar to those of AB. But meanwhile, DADB exhibits a series of advantages over AB that merit its potential hydrogen storage application, such as lower dehydrogenation temperature, free of foaming and lack of an induction period in the thermal decomposition process. Our study further found that the volatile non-hydrogen products from DADB can be effectively suppressed by milling with MgH(2).
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: Zhanzhao
authors.initials: Z
authors.lastname: Fang
authors.forename: Junhong
authors.initials: J
authors.lastname: Luo
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Kang
authors.forename: Haijie
authors.initials: H
authors.lastname: Xia
authors.forename: Sisheng
authors.initials: S
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Wen
authors.forename: Xingtai
authors.initials: X
authors.lastname: Zhou
authors.forename: Ping
authors.initials: P
authors.lastname: Wang