The regulation of the metal-support interaction in heterogeneous catalysts can promote the activation of reactants, which is beneficial for the hydrolytic dehydrogenation reaction. Herein, the hydrolytic dehydrogenation of dimethylamine borane (DMAB) is systematically studied on the oxygen vacancy (O v ) enriched Pt-Co 3 O 4 heterogeneous catalyst with the metal-support interaction. It is found that the metallic Pt site facilitates the adsorption of DMAB molecules and the O v on Co 3 O 4 support as an electron-rich center cooperates with the adjacent Pt site to dissociate water molecules. The in situ Raman and attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy reveal the effective activation and cleavage of the O-H in water and the B-H in DMAB over the Pt-Co 3 O 4 catalyst. The optimal Pt-Co 3 O 4 catalyst exhibits the extraordinary activity for the catalytic hydrolysis of DMAB at 303 K, delivering a high specific hydrogen generation rate (64063 mL min −1 g pt −1 ) and a competitive turnover frequency (TOF, 23880 mol H2 mol Pt −1 h −1 ). This performance outperforms most of the reported heterogeneous catalysts for DMAB dehydrogenation . More importantly, the Pt-Co 3 O 4 catalyst achieves the desirable on-demand hydrogen production by using special chemical switches. This finding provides the fundamental understanding of metal-oxide systems with the collaborative interfacial catalysis for boosting DMAB dehydrogenation .
Jing Jiang,Wei Wei,Zhen Ren,Yang Luo,Xinzhi Wang,Ying Xu,Mingming Chang,Lunhong Ai
Developing efficient catalysts for the dehydrogenation of ammonia borane (AB) is important for the safe storage and controlled release of hydrogen, but it is a challenging task. In this study, we designed a robust Ru-Co 3 O 4 catalyst using the Mott-Schottky effect to induce favorable charge rearrangement. The self-created electron-rich Co 3 O 4 and electron-deficient Ru sites at heterointerfaces are indispensable for the activation of the B-H bond in NH 3 BH 3 and the O H bond in H 2 O, respectively. The synergistic electronic interaction between the electron-rich Co 3 O 4 and electron-deficient Ru sites at the heterointerfaces resulted in an optimal Ru-Co 3 O 4 heterostructure that exhibited outstanding catalytic activity for the hydrolysis of AB in the presence of NaOH. The heterostructure had an extremely high hydrogen generation rate (HGR) of 12238 mL min −1 g cat -1 and an expected high turnover frequency (TOF) of 755 mol H2 mol Ru -1 min −1 at 298 K. The activation energy needed for the hydrolysis was low (36.65 kJ mol −1 ). This study opens up a new avenue for the rational design of high-performance catalysts for AB dehydrogenation based on the Mott-Schottky effect.