Palladium catalyzes hydrogen production from formic acid: significant impact of support polypyrrole

As a simple and promising hydrogen carrier, hydrogen production from formic acid (HCOOH) has been extensively investigated, owing to the properties of colorlessness, non-toxicity, and safety of formic acid.

Carbon-Supported Trimetallic Catalysts (PdAuNi/C) for Borohydride Oxidation Reaction

The synthesis of palladium-based trimetallic catalysts via a facile and scalable synthesis procedure was shown to yield highly promising materials for borohydride-based fuel cells, which are attractive for use in compact environments. This, thereby, provides a route to more environmentally friendly energy storage and generation systems. Carbon-supported trimetallic catalysts were herein prepared by three different routes: using a NaBH₄-ethylene glycol complex (PdAuNi/C_SBEG), a NaBH₄-2-propanol complex (PdAuNi/C_SBIPA), and a three-step route (PdAuNi/C_3-step). Notably, PdAuNi/C_SBIPA yielded highly dispersed trimetallic alloy particles, as determined by XRD, EDX, ICP-OES, XPS, and TEM. The activity of the catalysts for borohydride oxidation reaction was assessed by cyclic voltammetry and RDE-based procedures, with results referenced to a Pd/C catalyst. A number of exchanged electrons close to eight was obtained for PdAuNi/C_3-step and PdAuNi/C_SBIPA (7.4 and 7.1, respectively), while the others, PdAuNi/C_SBEG and Pd/C_SBIPA, presented lower values, 2.8 and 1.2, respectively. A direct borohydride-peroxide fuel cell employing PdAuNi/C_SBIPA catalyst in the anode attained a power density of 47.5 mW cm⁻² at room temperature, while the elevation of temperature to 75 °C led to an approximately four-fold increase in power density to 175 mW cm⁻². Trimetallic catalysts prepared via this synthesis route have significant potential for future development.

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.

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.

Ultrafine PdAu nanoparticles immobilized on amine functionalized carbon black toward fast dehydrogenation of formic acid at room temperature

Ultrafine and highly dispersed PdAu nanoparticles were immobilized on amine functionalized carbon black (VXC-72-NH₂) for dehydrogenation of formic acid (FA). The introduction of amines is of vital importance for the formation of ultrafine PdAu nanoparticles (∼1.5 nm). Moreover, the presence of the amino groups also increased the electron density of PdAu nanoparticles, and this effect facilitated the formation of metal-formate, which further enhanced the rate of the catalytic dehydrogenation of FA. The as-prepared Pd_0.6Au_0.4/VXC-72-NH₂ exhibited high catalytic activity and 100% H₂ selectivity for dehydrogenation of formic acid without any additive, with turnover frequency (TOF) values of 7385 h^-1 at 298 K and 17 724 h^-1 at 333 K, which are the highest TOF values ever reported among heterogeneous catalysts for FA dehydrogenation.

Anchoring ultrafine RhNi nanoparticles on titanium carbides/manganese oxide as an efficient catalyst for hydrogen generation from hydrous hydrazine

RhNi NPs of 2.8 nm are successfully monodispersed on the bi-support MnO_x/MXene surface.