Synergistic Catalysis of Binary RuP Nanoclusters on Nitrogen-Functionalized Hollow Mesoporous Carbon in Hydrogen Production from the Hydrolysis of Ammonia Borane

Abstract

Exploring highly efficient nanocatalysts for hydrogen (H 2 ) production from catalytic hydrolysis of ammonia borane (AB) under ambient conditions and further unveiling their catalytic mechanism are of critical importance for renewable energy conversion technologies but remain big challenges. Herein, ultrafine binary RuP alloy nanoclusters homogeneously encapsulated onto nitrogen-functionalized hollow mesoporous carbon supports (RuP@NHMCs) are reported as a high-performance platinum (Pt)free nanocatalyst for catalytic hydrolysis of AB at room temperature. Remarkable catalytic activity with a very high turnover frequency of 1774 mol H 2 mol Ru −1 min −1 and a low activation energy of 36.3 kJ mol −1 is observed based on compositional and structural synergies of RuP@NHMCs. Results of control experiments and catalytic kinetics studies reveal that the rate-determining step of catalytic hydrolysis of AB is the oxidation cleavage of a covalently stable H−OH bond, while RuP@NHMCs result in multiple electronic, functional, size, and support effects that kinetically accelerate the cleavage of attacked H− OH. Furthermore, RuP@NHMCs exhibit a good catalytic activity with a high yield of >99% for tandem hydrogenation of nitroarenes coupled with the hydrolysis of AB. We strongly believe that the catalyst design principle reported here could provide a new opportunity for synthesizing other Pt-free high-performance nanocatalysts.

Ru Nanoparticles Immobilized on Chitosan as Effective Catalysts for Boosting NH3BH3 Hydrolysis

“…The corresponding TOF value is 111.1, 238.2, 325.1, 331.8 min −1 when the NaOH concentration is 0, 0.4, 0.8 and 1.2 M, respectively (Figure 10b). This can be ascribed to the coordination of OH − ions with the surface of Ru NPs, providing more electron for the Ru/CS catalysts, thus accelerating the oxidation of the O−H bond of water [46] . On the other hand, when further increasing the NaOH concentration to 1.6 M, an opposite behavior happens, and the corresponding TOF value reduces to 263.1 min −1 .…”

“…Literature reveals that the cleavage of the O−H bond of water is the rate‐determining step of AB hydrolysis [Eqs. (3–6)] [46] . To further improve the reaction rate, we studied the effect of different NaOH concentrations, and the results are shown in Figure 10.…”

Copper(II)‐Assisted Ammonia Borane Dehydrogenation: An Insight

“…In our case, Cu 2 + being strongly electron deficient readily react with BÀ H bond of AB. [37][38][39][40] In subsequent step, [CuH] + Cl can undergo disproportionation reaction to give CuH, CuCl and HCl. As Cl[H 2 BNH 3 ] is not a stable species in water, it readily undergoes hydrolysis to B(OH) 3 and H 2 .…”

Precise Synthesis of Hollow Mesoporous Palladium–Sulfur Alloy Nanoparticles for Selective Catalytic Hydrogenation

“…23,[33][34][35][36][37][38] However, limited success has been achieved in applying the geometric effect of (hollow) mesoporous metals to adjust the selectivity of the products in hydrogenation reactions, although supported metal nanoclusters within mesoporous matrixes have been studied to enhance catalytic activity. [39][40][41] Hollow mesoporous metal nanocrystals were synthesized through templating strategies. Their mesoporous frameworks are formed by nucleation and growth of metal atoms around the self-assembled surfactants, while their interior nanocavity is generated by sequential removal of the sacrificial templates.…”