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Nanoporous Co100-xNix (x = 1, 5, 10 and 15) solid solutions were synthesized using the chemical coprecipitation followed by hydrogen reduction method and applied as catalysts for the efficient hydrogen generation from NaBH4 hydrolysis. The obtained catalysts are composed of hcp- and fcc-(Co,Ni) solid solutions phases, and exhibit the special three-dimensional nanoporous structure. With increasing the Ni content, the hydrogen generation rate (HGR) of NaBH4 hydrolysis catalyzed by Co100-xNix solid solutions decreased slightly, whereas the cycling stability of the catalyst can be improved. The HGR remains as much as 73% of the initial value after five times of catalysis for Co85Ni15. This work contributes to the development of advanced non-noble metal-based catalysts for efficient and long-term hydrogen generation from NaBH4 hydrolysis. [ABSTRACT FROM AUTHOR]

Slow hydrogen desorption kinetics and poor cycle durability of MgH2 still remain as challenges for practical applications. In this work, a new approach is proposed to synthesize few-layer MXene Ti3C2Tx supported Ni@C nanoflakes (Ni@C/FL-Ti3C2Tx), which can serve as a highly efficient catalyst for hydrogen desorption of MgH2. After ball milling under a 4 MPa hydrogen atmosphere for 15 hours, the MgH2–10 wt% Ni@C/FL-Ti3C2Tx composite exhibits superior hydrogen desorption kinetics and excellent cycling stability. Further investigation reveals that the enhancement of hydrogen storage properties is attributed to the in situ formed Mg2NiH4 and metallic Ti nanoparticles with a fine size and high dispersity as well as the FL-Ti3C2Tx nanosheets themselves. This work not only reports an effective strategy for improving the hydrogen storage properties of Mg-based materials but provides new insights into the underlying mechanism for optimizing the properties. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells with high energy conversion efficiency and low hazard emissions have aroused great attention from both academic and industrial communities, but their large-scale commercial application has been blocked by high costs as well as short lifespan of the anode Pt catalysts. Here, we demonstrate a simple and scalable noncovalent strategy for the synthesis of quasi-one-dimensional (1D) Pt nanoworms grown on poly(diallyldimethyl-ammonium chloride) (PDDA)-functionalized Ti 3 C 2 T x nanosheets as anode catalysts for methanol electrooxidation. Interestingly, the introduction of PDDA on Ti 3 C 2 T x nanosheets can not only effectively adjust their surface charge property to strengthen the electrostatic interaction between metal and support but also induce the stereoassembly of worm-shaped Pt nanocrystals with abundant catalytically active grain boundaries, which enable the resulting hybrid to express high electrocatalytic activity, remarkable durability, and strong antipoisoning ability for methanol electrooxidation, which are better than those of the traditional Pt nanoparticle electrocatalysts loaded on carbon black, carbon nanotubes, reduced graphene oxide, and MXene matrixes. Theoretical simulations disclose that the more stable worm-shaped Pt configuration with an optimized electronic structure on the Ti 3 C 2 T x surface possesses a weaker CO adsorption ability than that of the Pt nanoclusters, thereby providing a dramatically enhanced and sustainable electrocatalytic performance.