L. Wang et al., HIGH-RESOLUTION ELECTRON-MICROSCOPY CHARACTERIZATION OF PARTIALLY CRYSTALLIZED FE78SI12B10 ALLOY AS A CATALYST, Journal of Materials Science, 28(18), 1993, pp. 4835-4840
As a catalyst, partially crystallized Fe78Si12B10 alloy shows a three
times higher activity than totally crystallized Fe78Si12B10 in the hyd
rogenation of CO. High-resolution electron microscopy (HREM) reveals t
hat the catalyst contains a great number of minute (less than 1 0 nm),
highly dispersed alpha-Fe particles which act as the major active com
ponent. Many tiny B and Si oxide clusters also exist in the amorphous
matrix. After being rinsed by a NaOH solution, the catalyst exhibits a
decreasing selectivity to methane due to the dissolution or aggregati
on of B and Si species. After reaction, the sizes of the active partic
les increase and an overlayer of B or Si species is found over the sur
face of some alpha-Fe particles. This coverage is thought to be the pr
imary origin of the deactivation of the catalyst.