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Ammonia borane (AB), a liquid hydrogen storage material, has attracted increasing attention for hydrogen utilization because of its high hydrogen content. However, the slow kinetics of AB hydrolysis and the indefinite catalytic mechanism remain significant problems for its large-scale practical application. Thus, the development of efficient AB hydrolysis catalysts and the determination of their catalytic mechanisms are significant and urgent. A summary of the preparation process and structural characteristics of various supported catalysts is presented in this paper, including graphite, metal-organic frameworks (MOFs), metal oxides, carbon nitride (CN), molybdenum carbide (MoC), carbon nanotubes (CNTs), boron nitride (h-BN), zeolites, carbon dots (CDs), and metal carbide and nitride (MXene). In addition, the relationship between the electronic structure and catalytic performance is discussed to ascertain the actual active sites in the catalytic process. The mechanism of AB hydrolysis catalysis is systematically discussed, and possible catalytic paths are summarized to provide theoretical considerations for the designing of efficient AB hydrolysis catalysts. Furthermore, three methods for stimulating AB from dehydrogenation by-products and the design of possible hydrogen product-regeneration systems are summarized. Finally, the remaining challenges and future research directions for the effective development of AB catalysts are discussed.

Creating active sites to improve the mass activity and durability of metal catalysts by elucidating the relationship between the metal and the support is a major challenge. In this study, ultrafine palladium nanoparticles (Pd NPs) were supported on alkalized Ti3C2 (alk-Ti3C2) to obtain a catalytically active interfacial ensemble. The catalyst Pd/alk-Ti3C2 with a Pd loading of 1.0 wt % exhibited the highest activity in ammonia borane (AB) hydrolysis reaction, with an initial turnover frequency of 230.6 min–1. A comprehensive analysis revealed that an ensemble-exciting effect originated from the Pd and the alk-Ti3C2. The hydroxylation of alk-Ti3C2 regulated the local coordination environment of Pd. Water and AB were effortlessly activated by the −OH group and Pd atom aggregates composed of electron-deficient support alk-Ti3C2 and electron-rich Pd, respectively. The efficient generation of hydrogen at the interface of Pd/alk-Ti3C2 was further guaranteed by the interfacial activation. This work on precision active sites opens new avenues for developing high-activity noble-metal catalysts for AB hydrolysis.

The rational design of the interface structure between nitride and oxide using the same metallic element and correlating the interfacial active center with a determined catalytic mechanism remain challenging. Herein, a Co4N‐Co3O4 interface structure is designed to determine the effect of interfacial active centers on hydrogen generation from ammonia borane. An unparalleled catalytic activity toward H2 production with a turnover frequency up to 79 min−1 is achieved on Co4N‐Co3O4@C catalyst for ten recycles. Experimental analyses and theoretical simulation suggest that the atomic interface‐exciting effect (AieE) is responsible for the high catalytic activity. The Co4N‐Co3O4 interface facilitates the targeted adsorption and activation of NH3BH3 and H2O molecules to generate H* and H2. The two active centers of Co(N)* and Co(O)* at the Co4N‐Co3O4 interface activate NH3BH3 and H2O, respectively. This proof‐of‐concept research on AieE provides important insights regarding the design of heterogeneous catalysts and promotes the development of the nature and regulation of energy chemical conversion.

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Highly active and stable non-noble metal catalysts are expected to play a critical role in future hydrogen storage and conversion applications. The design of active sites with composite oxides provides a new approach for developing high-performance catalysts. In this study, an Fe-doped Ni/NiO nanocomposite film was constructed on an ionic liquid/water interface to promote hydrogen generation. The optimized Ni/FeNiO x -25 catalyst showed excellent catalytic activity toward ammonia borane hydrolysis, with a turnover frequency of 72.3 min–1. The enhancing effect of Fe2+ doping on Ni/NiO films was confirmed by the improved intrinsic activity and theoretical simulations. Fe ion doping stabilized NiO and prevented NiO from becoming Ni. The interfacial Ni–Fe2+ dual active sites on the FeNiO x and Ni interfaces participated in the targeted adsorption and effective activation of water and NH3BH3 molecules, respectively. The sufficiently exposed plane surface of the nanofilms provided abundant active sites for catalytic reactions. This significant advance will inspire development in the ambient liquid hydrogen storage field.

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