Chitosan-derived carbon aerogel stabilized Ru nanoparticles: Facile fabrication and application in catalyzing NH3BH3 hydrolytic dehydrogenation

Developing a convenient and environmental-friendly catalyst preparation method is of great significance, while the catalytic hydrolysis of ammonia borane (NH 3 BH 3 , AB) is an effective in-situ hydrogen production strategy but faces many challenges including the absence of practicable catalysts. In this study, Ru nanoparticles are tightly encapsulated into the framework of chitosan (CS)-derived carbon aerogel (CCA) through a facile ice-crystal template method combined with one-step direct calcination without using any additional chemical activators. The exciting coordination between Ru 3+ and the N/O-based functional groups of CS in aqueous solution, the hierarchical porous structure of CCA and the self-doped N/O favor the tight and high dispersion of Ru NPs, facilitate mass transfer, as well as improve the hydrophilicity of the resulting catalysts. Therefore, the resulting catalysts exhibit excellent activity and durability in the hydrolytic dehydrogenation of AB. Activated by the optimal [email protected] , the turnover frequency (TOF) and hydrogen generation rate (HGR) in the absence of any strong base are separately 136.6 min −1 and 30.3 × 10 3 mL min −1 g Ru −1 , and the apparent activation energy is 42.1 kJ mol −1 . Interestingly, the introduction of NaOH (2.0 M) can further significantly accelerate hydrogen release (TOF = 562.9 min −1 , HGR = 124.7 × 10 3 mL min −1 g Ru −1 ). Additionally, the kinetic isotope effect of 2.82 recommends that an O–H bond dissociation in water acts a dominant role in AB hydrolysis over [email protected] . This work develops a facile and environmentally friendly method for preparing supported metal-based nanocatalysts that can be effectively used in many reactions including AB hydrolysis.