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Constructing uniformly coated Mg nanoparticles (NPs) with the addition of the Al−V alloy nanocatalyst and retaining the stability of the core@shell structure are challenging issues. In this work, a novel Mg@Mg 17 Al 12 nanocomposite of 120 nm decorated with Al 3 V (5 nm) NPs is prepared by the hydrogen plasma metal reaction method. After the first hydrogenation process at 673 K, the Mg 17 Al 12 shell of 3 nm disproportionates into an Al shell and MgH 2 core, while Al 3 V changes into AlV 3 and Al. After the hydrogenation/dehydrogenation cycle, the Mg 17 Al 12 shell is obtained again, whereas AlV 3 remains unchanged. The nanocomposite can quickly uptake 5.0 wt % H 2 within 30 min at 473 K, and the hydrogen absorption capacities of the nanocomposite are almost stable at 6.3 wt % above 473 K. It can release 4.0 wt % H 2 within 10 min at 573 K. The apparent activation energies for hydrogen absorption and desorption are decreased to 43.3 and 44.7 kJ/ mol H 2 . The AlV 3 nanocatalyst can store hydrogen of 1.0 wt % at 473 K, and the first-principles calculation also implies that the hydrogen dissociation energy on the AlV 3 surface is 0.76 eV, much lower than Mg (0.92 eV). Both experimental and calculation results prove AlV 3 to be a novel and effective nanocatalyst.

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Tourism is currently one of the important development industries in many countries and regions, and a healthy environment is an important basis and carrier for the sustainable development of the tourism economy. Ensuring a harmonious relationship between tourism, the economy, and the environment has become one of the keys to achieving sustainable development of tourism destinations. Based on panel data on tourism, the economy, and the environment from nine provinces along the Silk Road Economic Belt from 2015 to 2019, this study has built a comprehensive evaluation index system of the tourism–economy–ecological environment (TEE). The entropy evaluation method, comprehensive evaluation model, and coupling and coordination degree model were used for quantitative analysis of the coordination development level and for assessing the spatial–temporal evolution patterns of coupling coordination for the TEE system in nine provinces along the Silk Road Economic Belt. The results show that the value of the TEE system is generally on the rise. Still, the growth rate of tourism and the economy subsystem is significantly higher than that of the environment subsystem. The coupling coordinating the development of the TEE system shows an increasing trend with a high degree of coupling. The coordination degree is relatively low, with significant gradient differences and apparent polarization. The main constraint to the coordinated development of the Silk Road Economic Belt is tourism and the economy.