Tetraglyme-mediated synthesis of Pd nanoparticles for dehydrogenation of ammonia borane

Mechanistic insights into the thermal decomposition of ammonia borane, a material studied for chemical hydrogen storage

We have now a better understanding of the mechanisms of thermal decomposition of ammonia borane, a widely studied hydrogen storage material.

In situ synthesized hollow spheres of a silica–ruthenium–nickel composite catalyst for the hydrolytic dehydrogenation of ammonia borane

The present study investigated the fabrication of hollow spheres of a silica–ruthenium–nickel composite catalyst for the hydrolitic dehydrogenation of ammonia borane.

Ni0.5Cu0.5Co2O4 Nanocomposites, Morphology, Controlled Synthesis, and Catalytic Performance in the Hydrolysis of Ammonia Borane for Hydrogen Production

The catalytic hydrolysis of ammonia borane (AB) is a promising route to produce hydrogen for mobile hydrogen‒oxygen fuel cells. In this study, we have successfully synthesized a variety of Ni_0.5Cu_0.5Co₂O₄ nanocomposites with different morphology, including nanoplatelets, nanoparticles, and urchin-like microspheres. The catalytic performance of those Ni_0.5Cu_0.5Co₂O₄ composites in AB hydrolysis is investigated. The Ni_0.5Cu_0.5Co₂O₄ nanoplatelets show the best catalytic performance despite having the smallest specific surface area, with a turnover frequency (TOF) of 80.2 mol_hydrogen·min^-1·mol^-1_cat. The results reveal that, in contrast to the Ni_0.5Cu_0.5Co₂O₄ nanoparticles and microspheres, the Ni_0.5Cu_0.5Co₂O₄ nanoplatelets are more readily reduced, leading to the fast formation of active species for AB hydrolysis. These findings provide some insight into the design of high-performance oxide-based catalysts for AB hydrolysis. Considering their low cost and high catalytic activity, Ni_0.5Cu_0.5Co₂O₄ nanoplatelets are a strong candidate catalyst for the production of hydrogen through AB hydrolysis in practical applications.

Sub-3 nm Rh nanoclusters confined within a metal–organic framework for enhanced hydrogen generation

Rh@UIO-66, prepared by using the double-solvent host–guest strategy and excess reduction methods, exhibited a higher catalytic activity in AB hydrolysis compared with Rh/UIO-66 because the ultrafine Rh nanoparticles were confined to UIO-66 channels. This confinement effect played a key role in enhancing the catalytic activity for AB hydrolysis.

MoO₃-Doped MnCo₂O₄ Microspheres Consisting of Nanosheets: An Inexpensive Nanostructured Catalyst to Hydrolyze Ammonia Borane for Hydrogen Generation

Production of hydrogen by catalytically hydrolyzing ammonia borane (AB) has attracted extensive attention in the field of catalysis and energy. However, it is still a challenge to develop a both inexpensive and active catalyst for AB hydrolysis. In this work, we designed a series of MoO₃-doped MnCo₂O₄ (x) catalysts, which were fabricated by a hydrothermal process. The morphology, crystalline structure, and chemical components of the catalysts were systematically analyzed. The catalytic behavior of the catalyst in AB hydrolysis was investigated. Among these catalysts, MoO₃-doped MnCo₂O₄ (0.10) microspheres composed of nanosheets exhibited the highest catalytic activity. The apparent activation energy is 34.24 kJ mol⁻¹ and the corresponding turnover frequency is 26.4 mol_hydrogen min⁻¹ mol_cat⁻¹. Taking into consideration the low cost and high performance, the MoO₃-doped MnCo₂O₄ (0.10) microspheres composed of nanosheets represent a promising catalyst to hydrolyze AB for hydrogen production.

Magnetic, recyclable PtyCo1−y/Ti3C2X2 (X = O, F) catalyst: a facile synthesis and enhanced catalytic activity for hydrogen generation from the hydrolysis of ammonia borane

Magnetic recyclable Pt_yCo_1−y/Ti₃C₂X₂ (X = O, F) catalyst exhibits excellent catalytic performance for the hydrolysis of AB at room temperature.

Hydrothermal Synthesis and Catalytic Application of Ultrathin Rhodium Nanosheet Nanoassemblies

Ultrathin noble metal nanosheets with atomic thickness exhibit abnormal electronic, surfacial, and photonic properties due to the unique two-dimensional (2D) confinement effect, which have attracted intensive research attention in catalysis/electrocatalysis. In this work, the well-defined ultrathin Rh nanosheet nanoassemblies with dendritic morphology are synthesized by a facile hydrothermal method with assistance of poly(allylamine hydrochloride) (PAH), where PAH effectively acts as the complexant and shape-directing agent. Transmission electron microscopy and atomic force microscopy images reveal the thickness of 2D Rh nanosheet with (111) planes is only ca. 0.8-1.1 nm. Nitrogen adsorption-desorption measurement displays the specific surface area of the as-prepared ultrathin Rh nanosheet nanoassemblies is 139.4 m² g^-1, which is much bigger than that of homemade Rh black (19.8 m² g^-1). Detailed catalytic investigations display the as-prepared ultrathin Rh nanosheet nanoassemblies have nearly 20.4-fold enhancement in mass-activity for the hydrolysis of ammonia borane as compared with homemade Rh black.

Growth kinetics of white graphene (h-BN) on a planarised Ni foil surface

The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD). We report a correlation between the growth rate of h-BN and the orientation of the nickel grains. The surface of the nickel (Ni) foil was first polished by electrochemical polishing (ECP) and subsequently annealed in hydrogen at atmospheric pressure to suppress the effect of the surface morphology. Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil. A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy.

Non-noble bimetallic CuCo nanoparticles encapsulated in the pores of metal–organic frameworks: synergetic catalysis in the hydrolysis of ammonia borane for hydrogen generation

Non-noble bimetallic CuCo alloy nanoparticles were successfully encapsulated in the pores of MIL-101 without aggregation on the external surfaces of the host framework, which exhibit excellent catalytic activity for hydrolytic dehydrogenation of ammonia borane.

Surfactant free RGO/Pd nanocomposites as highly active heterogeneous catalysts for the hydrolytic dehydrogenation of ammonia borane for chemical hydrogen storage

In this study, monodisperse palladium (Pd) nanoparticles on reduced graphene oxide (RGO) surfaces were successfully prepared by a "wet" and "clean" method in aqueous solution. Without any surface treatment, Pd nanoparticles are firmly attached to the RGO sheets. These RGO/Pd nanocomposites exhibited catalytic activity in hydrogen generation from the hydrolysis of ammonia borane (AB). Their hydrolysis completion time and activation energy were 12.5 min and 51 ± 1 kJ mol(-1), respectively, which were comparable to the best Pd-based catalyst reported. The TOF values (mol of H(2)× (mol of catalyst × min)(-1)) of RGO/Pd is 6.25, which appears to be one of the best catalysts reported so far. We also obtained a (11)B NMR spectrum to investigate the mechanism of this catalytic hydrolysis process. This simple and straightforward method is of significance for the facile preparation of metal nanocatalysts with high catalytic activity on proper supporting materials.