Hydrogen has emerged as an environmentally attractive fuel and a promising energy carrier for future applications to meet the ever-increasing energy challenges. The safe and efficient storage and release of hydrogen remain a bottleneck for realizing the upcoming hydrogen economy. Hydrogen storage based on liquid-phase chemical hydrogen storage materials is one of the most promising hydrogen storage techniques, which offers considerable potential for large-scale practical applications for its excellent safety, great convenience, and high efficiency. Recently, nanopore-supported metal nanocatalysts have stood out remarkably in boosting the field of liquid-phase chemical hydrogen storage. Herein, the latest research progress in catalytic hydrogen production is summarized, from liquid-phase chemical hydrogen storage materials, such as formic acid, ammonia borane, hydrous hydrazine, and sodium borohydride, by using metal nanocatalysts confined within diverse nanoporous materials, such as metal-organic frameworks, porous carbons, zeolites, mesoporous silica, and porous organic polymers. The state-of-the-art synthetic strategies and advanced characterizations for these nanocatalysts, as well as their catalytic performances in hydrogen generation, are presented. The limitation of each hydrogen storage system and future challenges and opportunities on this subject are also discussed. References in related fields are provided, and more developments and applications to achieve hydrogen energy will be inspired.

Nanopore-Supported Metal Nanocatalysts for Efficient Hydrogen Generation from Liquid-Phase Chemical Hydrogen Storage Materials

Palladium nanoclusters decorated partially decomposed porous ZIF-67 polyhedron with ultrahigh catalytic activity and stability on hydrogen generation

The synthesis, characterization, and catalytic studies of platinum (Pt) nanoparticles (NPs) supported by a polymer-derived SiCN matrix are reported. In the first step and under mild conditions (110 °C), a block copolymer (BCP) based on hydroxyl-group-terminated linear polyethylene (PEOH) and a commercially available polysilazane (PSZ: HTT 1800) were synthesized. Afterwards, the BCP was microphase separated, modified with an aminopyridinato (Ap) ligand-stabilized Pt complex, and cross-linked. The green bodies thus obtained were pyrolyzed at 1000 °C under nitrogen and provided porous Pt@SiCN nanocomposite via decomposition of the PEOH block while Pt nanoparticles grew in situ within the SiCN matrix. Powder X-ray diffraction (PXRD) studies confirmed the presence of the cubic Pt phase in the amorphous SiCN matrix whereas transmission electron microscopy (TEM) measurements revealed homogeneously distributed Pt nanoparticles in the size of 0.9 to 1.9 nm. N2 sorption studies indicated the presence of micro- and mesopores. Pt@SiCN appears to be an active and robust catalyst in the hydrolysis of sodium borohydride under harsh conditions.

Micro‐/Mesoporous Platinum–SiCN Nanocomposite Catalysts (Pt@SiCN): From Design to Catalytic Applications

Designing a highly active and stable catalyst for NaBH4 hydrolysis is a key step towards overcoming the challenges of hydrogen storage. Herein, we have developed a controllable strategy to fabricate a series of hierarchically structured cobalt-ruthenium-phosphide arrays on nickel foam (Co–Ru–P@NF) as a highly efficient and stable catalyst for hydrogen generation from NaBH4 hydrolysis in alkaline media. SEM and TEM analyses show that the interconnected rugae-like Co–Ru–P arrays are vertically grown on the surface of Ni foam, together with uniformly distributed RuP3 nanoclusters on the surface of CoP nanosheets. More importantly, the optimized Co–Ru–P@NF catalyst exhibits an outstanding catalytic performance on NaBH4 hydrolysis in alkaline media with a high turnover frequency (TOF) of 2123.6 molH2 min−1 molRu−1 at 25 °C, which is one of the highest known so far. Furthermore, the exceptional catalytic performance is in line with the outcome of low activation energy (40.3 kJ mol−1). Additionally, the catalyst also shows a high stability with less than 8.0% lost after 5 consecutive cycles. The superior catalytic performance is ascribed to the synergetic effect between RuP3 and CoP species resulting in a significant electron transfer effect, together with the unique morphologies associated with a large specific surface area and open-channels for effective solute transport/adsorption and H2 gas emissions.

Hierarchically structured rugae-like RuP3–CoP arrays as robust catalysts synergistically promoting hydrogen generation

A new and reusable hybrid catalyst of Pt/CeO2–Co7Ni2Ox is fabricated readily, in which a high dispersion of Pt atomic cluster is successfully achieved by the introduction of CeO2. The oxidation states of each elemental metal in varied compositions are studied systematically to design the catalyst. The optimal Pt/CeO2–Co7Ni2Ox catalyst exhibits an extremely high specific H2 evolution rate of 7834.8 mLH2 min–1 gcat–1 and turnover frequency of 679.0 molH2 min–1 molPt–1 for the hydrolysis of alkalized NaBH4 solution. It is one of the most efficient catalysts so far, and the reason is ascribed to the lower activation energy (47.4 kJ mol–1) as we confirmed. The lower energy barrier and high performances mainly results from the ultrasmall Pt atomic clusters, which have more active sites to adsorb and break the B–H bonds in BH4– ions for the generation of negative charged H– via electron transfer, and then the H– can immediately combine with the positive charged H+ (originated from the weakened H–O–H bond on the ...

Ceria-Induced Strategy To Tailor Pt Atomic Clusters on Cobalt–Nickel Oxide and the Synergetic Effect for Superior Hydrogen Generation

Organosilicon polymer-derived mesoporous 3D silicon carbide, carbonitride and nitride structures as platinum supports for hydrogen generation by hydrolysis of sodium borohydride

Awin Wasan

Papers

Organosilicon polymer-derived mesoporous 3D silicon carbide, carbonitride and nitride structures as platinum supports for hydrogen generation by hydrolysis of sodium borohydride