Enhanced catalytic performance of cobalt ferrite by a facile reductive treatment for H2 release from ammonia borane

Abstract

Although magnetic cobalt ferrite (CoFe2O4) has been applied as support to gain magnetically separable nanocomposites for H2 evolution upon the hydrolytic dehydrogenation of ammonia borane (AB), none of them find that only CoFe2O4 could be used as the efficient catalyst for the H2 evolution. Herein, we report a facile reduction strategy to significantly improve the catalytic activity of CoFe2O4 by producing more oxygen vacancies and enhencing surface adsorbed oxygen species. The reduced CoFe2O4 catalyst exhibited superior catalytic activity for H2 evolution upon hydrolytic dehydrogenation of AB, with a TOF of 245 mol(H2)·molcat-1·h−1, whereas the pristine CoFe2O4 does not work. Interestingly the TOF of reduced CoFe2O4 in the H2 evolution increased sharply from 245 to 390 mol(H2)·molcat-1·h−1 in the presence of NaOH. In addition, as-prepared reduced CoFe2O4 has been successfully reused at least 5 cycles without any catalytic activity loss in the hydrolytic dehydrogenation of AB.