Porous nitrogen-doped carbon-immobilized bimetallic nanoparticles as highly efficient catalysts for hydrogen generation from hydrolysis of ammonia borane

Abstract

Two N-doped carbon materials, N-doped Vulcan XC-72 carbon labelled as NXC and graphite carbon nitride labelled as C3N4, were selected as supports to prepare a series of bimetallic AuM (M = Co, Ni) nanoparticles (NPs) using three different reduction ways towards mixed metal ions AuCl4 − and M 2+ , and then the as-synthesized supported bimetallic AuM NPs were used as catalysts for hydrolytic dehydrogenation of ammonia borane (NH3BH3). All the catalysts exhibited high dispersion and small size of bimetallic NPs; however, they exhibited remarkably different catalytic activities featuring total turnover frequency (TOF) values from 6.4 to 42.1 molH2⋅molcat -1 ⋅min -1 . Among all the catalysts, the NXC-immobilized AuCo NPs through in situ synthesis using NaBH4 and NH3BH3 as reductants exhibited the highest activity with a total TOF value of 42.1 molH2⋅molcat -1 ⋅min -1 , which was among the highest values for Co-based catalysts ever reported for hydrolytic dehydrogenation of NH3BH3. This remarkably enhanced activity may be attributed to the synergistic effect of N-doped NXC support and AuCo NPs and the resulting highly efficient activation of N-B bond in NH3BH3. In addition, the AuCo catalysts showed good recyclability, demonstrating that they had high stability/durability.High-performance hydrogen generation from hydrolysis of ammonia borane has been achieved over porous nitrogen-doped carbon-immobilized bimetallic nanoparticles.

Mesoporous Carbon Nitride Supported Pd and Pd‐Ni Nanoparticles as Highly Efficient Catalyst for Catalytic Hydrolysis of NH3BH3

“…Pd is less expensive than Pt and Rh, but it is also modestly active . To minimize the usage of noble metals, the synthesis of bimetallic nanocatalysts with non‐noble metal elements has attracted considerable research interest in recent years . Additionally, appropriate supports have been employed to enhance the stability and dispersibility of metal NPs, such as carbon materials, mesostructured materials, metal oxides, metal‐organic frameworks, etc.…”

“…The synergistic effect between Pd and Ni is caused by the different local strain and effective atomic coordination number on the metal surface, which can tailor the surface electronic structure and catalytic performance. Similar synergetic interactions in bimetallic catalysts have been demonstrated in literature …”

Synthesis, Characterization, and Application of Metal Nanoparticles Supported on Nitrogen‐Doped Carbon: Catalysis beyond Electrochemistry

“…In this context, Shaabani and Mahyari [23] prepared Ni NPs immobilized on three-dimensional N-doped graphene based frameworks (NiNPs@3D-(N)GFs) as hydrolysis catalysts.C ompared to other Ni-based catalysts,t he NiNPs@3D-(N)GFs were more active.W ith NaBH 4 and NH 3 BH 3 as in situ reductants,abimetallic AuCo/N-C catalyst also performed very well in this hydrolysis. [98] In both cases, the interaction between the N-doped carbon and metal (or metal alloy) NPs was proposed to play av ital role in the activation of the NÀBbond in NH 3 BH 3 (Scheme 12).…”

Cobalt‐Based MOF‐Derived CoP/Hierarchical Porous Carbon (HPC) Composites as Robust Catalyst for Efficient Dehydrogenation of Ammonia‐Borane

“…Transition metal nanoparticles (NPs), characterized mainly by Fe, Co, Ni have gained considerable interests due to their low cost, easy availability and special physicochemical properties . During past few years, a large amount of cost‐effective non‐noble metals and their alloy component have been developed and efficiently used to catalyze the hydrolysis reaction .…”