Highly monodispersed palladium-ruthenium alloy nanoparticles assembled on poly(N-vinyl-pyrrolidone) for dehydrocoupling of dimethylamine-borane: An experimental and density functional theory study

"On-Off" Control for On-Demand H2 Release upon Dimethylamineborane Hydrolysis over Ru0.8Ni0.2/MoS2 Nanohybrids

In spite of the fact that remarkable developments are achieved in the design and development of novel nanocatalysts for H₂ release upon dimethylamineborane hydrolysis, the development of an "on-off" switch for demand-based H₂ evolution upon dimethylamineborane hydrolysis is still a matter of supreme importance, however. Herein, we synthesized a string of MoS₂ nanosheet-supported RuNi bimetallic nanohybrids (Ru_xNi_1-x/MoS₂), by fixation of RuNi nanoparticles at the MoS₂ surface, for the H₂ evolution upon the hydrolysis of dimethylamineborane at 30 °C. For safely and effectively generating, transporting, and storing H₂ gas, the selective "on-off" switch for on-demand H₂ evolution upon dimethylamineborane hydrolysis over the Ru_0.8Ni_0.2/MoS₂ nanohybrid has been successfully realized by the Zn²⁺/EDTA-2Na system. In particular, the H₂ evolution is totally switched off by adding Zn(NO₃)₂. It seems that Zn²⁺ ions are attached and anchored at the Ru_0.8Ni_0.2/MoS₂ surface, inhibiting their surface-active sites, leading to the termination of H₂ evolution. Then, the H₂ generation is subsequently reactivated by adding the EDTA-2Na solution because of its excellent coordination ability with Zn²⁺ ions. This study not only offers a new and efficient RuNi nanocatalyst for dimethylamineborane hydrolysis but also proposes a new method for the demand-based H₂ production.

Recent developments of nanocatalyzed liquid-phase hydrogen generation

Hydrogen is the most effective and sustainable carrier of clean energy, and liquid-phase hydrogen storage materials with high hydrogen content, reversibility and good dehydrogenation kinetics are promising in view of "hydrogen economy". Efficient, low-cost, safe and selective hydrogen generation from chemical storage materials remains challenging, however. In this Review article, an overview of the recent achievements is provided, addressing the topic of nanocatalysis of hydrogen production from liquid-phase hydrogen storage materials including metal-boron hydrides, borane-nitrogen compounds, and liquid organic hydrides. The state-of-the-art catalysts range from high-performance nanocatalysts based on noble and non-noble metal nanoparticles (NPs) to emerging single-atom catalysts. Key aspects that are discussed include insights into the dehydrogenation mechanisms, regenerations from the spent liquid chemical hydrides, and tandem reactions using the in situ generated hydrogen. Finally, challenges, perspectives, and research directions for this area are envisaged.

A novel highly active and reusable carbon based platinum-ruthenium nanocatalyst for dimethylamine-borane dehydrogenation in water at room conditions

In this paper, we present platinum/ruthenium nanoparticles supported on Vulcan carbon (PtRu@VC) as a nanocatalyst for the dehydrogenation of dimethylamine-borane (DMAB) in aqueous solution under mild conditions. PtRu@VC nanocatalyst was fabricated using the alcohol-reduction techniques which is a facile and effective method. The prepared PtRu@VC nanocatalyst exhibited a good stabilization and an effective catalytic activity for hydrogen evolution from the DMAB dehydrogenation in water at room temperature. The composition of PtRu@VC nanocatalyst was investigated using different analytical techniques inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (P-XRD) and X-ray photoelectron spectroscopy (XPS). A monodispersedPt/Ru metals distributions on VC (as supporting material) were revealed by TEM and HR-TEM analyses. The mean particle size of PtRu@VC nanocatalyst was found to be 3.15 ± 0.76 nm. XPS analysis for PtRu@VC nanocatalyst showed that almost Pt-Ru metals were found to be the metallic state. Catalytic experimental results showed that PtRu@VC nanocatalyst has a high catalytic activity with an excellent turn-over frequency (TOF_initial) value of 14926.2 h⁻¹ (248.77 min⁻¹) in the dehydrogenation of DMAB in water at room temperature. Additionally, in the paper, we report some different kinetic data obtained from different experimental parameters of temperature, catalyst and substrate concentrations conducted for DMAB dehydrogenation in water catalyzed with PtRu@VC nanocatalyst.

Graphene quantum dot-sensitized Zn-MOFs for efficient visible-light-driven carbon dioxide reduction

A new hybrid Zn-Bim-His-1@GQD nanoparticle has been successfully developed for high selectivity of CO₂ reduction to yield CH₄.