Oxygen vacancy-attired dual-active-sites Cu/Cu0.76Co2.24O4 drives electron transfer for efficient ammonia borane dehydrogenation

Synergistic interface between metal Cu nanoparticles and CoO for highly efficient hydrogen production from ammonia borane

“…This may be due to the excess OH − species overlaying the active sites originally used for H coordination and H 2 dissociation. 15,31 The rate of generation of H 2 was found to be generally accelerated by NaOH, supporting that the rate-determining step in the hydrolysis reaction is the cleavage of the O–H bond in H 2 O.…”

“… 34 Wang and co-authors reported that a Cu/Cu 0.76 Co 2.24 O 4 double active site catalyst modified with oxygen vacancies ( V O ) significantly increased the H 2 production rate in the hydrolysis of NH 3 BH 3 . 31 Zhou et al fabricated CuNi bimetallic NPs anchored on Co 3 O 4 nanosheets, where the synergistic effect between Cu and Ni species and the strong interactions between CuNi and Co 3 O 4 afforded a maximum turnover frequency (TOF) of 31.5 mol H 2 mol metal −1 min −1 in 0.14 M NaOH at 298 K. 33 However, the addition of ineffective proportions of TMOs with non-ideal compositions leads to catalysts being produced with low intrinsic activity. Therefore, the optimisation of the interfacial effect of metals and TMOs to achieve the best catalytic performance remains a challenging task.…”

“…Multiple studies have shown that transition-metal oxides (TMOs) accelerate the activation of water molecules. [31][32][33] Therefore, a heterogeneous structure incorporating TMOs and metal NPs is an effective strategy for synthesising catalysts for hydrolysis reactions. Xu However, the addition of ineffective proportions of TMOs with non-ideal compositions leads to catalysts being produced with low intrinsic activity.…”

“…Multiple studies have shown that transition-metal oxides (TMOs) accelerate the activation of water molecules. 31–33 Therefore, a heterogeneous structure incorporating TMOs and metal NPs is an effective strategy for synthesising catalysts for hydrolysis reactions. Xu et al reported that a catalyst with a Cu–Co 3 O 4 interface greatly improves the hydrolysis performance of NH 3 BH 3 ; Cu effectively activates NH 3 BH 3 molecules and Co 3 O 4 effectively activates H 2 O molecules.…”

Ammonia borane as an efficient direct fuel in alkaline fuel cells: mechanism, catalysts, applications, and challenges

“…AB was applied in fuel cells in two ways: one is as a hydrogen storage material to produce H 2 16–20 and another is as an anode fuel directly. 21,22 As the indirect application of AB, the dehydrogenation of AB has been widely studied in recent years owing to its high gravimetric hydrogen density (19.6 wt% H), and there are three methods to promote the dehydrogenation of AB, including thermolysis, 23–26 hydrolysis, 16,27–29 and alcoholysis.…”