Amorphous to crystalline transformation of ultrafine Fe62B38 particles

Quasi in situ Mössbauer and XAS studies on FeB nanoalloy for heterogeneous catalytic dehydrogenation of ammonia borane

“…10) pattern of the postdehydrogenated Fe-doped AB is different from that of the Fe foil. Since ferric or ferrous salts are easy to be reduced by BH 4 − and alloy with B to form amorphous Fe-B alloys in solution [40,42], FeCl 2 in the sample may be reduced and alloy with B in AB during sample preparation and dehydrogenation treatment, which is confirmed by previous report [1] and Mössbauer characterization as mentioned above. The post-dehydrogenated sample shows a much broadened peak with the absence of high-order coordination peaks indicating an amorphous state of Fe species consistent with XRD results.…”

“…the short-range order and long-range disorder in structure [40][41][42]. Since the amorphous state of Fe species in our samples, quasi in situ 57 Fe Mössbauer spectroscopy were employed to identify the changes of chemical state and local environment of Fe during dehydrogenation process as shown in Fig.…”

Physicochemical and catalytic properties of Fe–P ultrafine amorphous catalysts

“…In particular, the ratio of different elements being not limited to the eutectic composition of the alloy. One of the most prominent methods is to prepare the amorphous alloys by chemical reduction of the metallic ions with hypophosphite (H 2 PO 2 − ) or borohydride (BH 4 − ) to form ultrafine metal boride or phosphide amorphous alloy particles, as first reported by van Wonterghem et al [70] and developed by Linderoth and Mørup et al [51,52,71]. The powder samples obtained by chemical reduction are highly dispersed to ensure large surface area of the resultant amorphous alloy catalysts, can be compacted in a variety of forms suitable for catalysis and can be used in catalytic test without any pretreatment, which makes them more convenient in catalytic studies.…”

Wet‐Chemical Synthesis of Nanoscale Iron Boride, XAFS Analysis and Crystallisation to α‐FeB

“…[22,28,29] In the present case, we applied extended X-ray absorption fine structure (EXAFS) to analyse iron boride precipitates.…”