To enhance the performance and durability of proton-exchange membrane fuel cells (PEMFCs), we looked beyond the polymer-skeleton electrospinning electrode and developed a novel carbon-skeleton nanofiber electrode (the C-spun electrode) by a facile heat-treatment process. After thermal annealing at 600 °C, part of the disordered Pt3Co nanoparticles converted into an ordered intermetallic phase, with an apparently improved oxygen reduction reaction (ORR) activity (E 1/2 increased by 50 mV). Meanwhile, the polymers in the polymer-skeleton nanofibers were carbonized and transformed into carbon skeletons, which exhibited excellent corrosion resistance during extensive carbon corrosion testings (1.0–1.5 V, 0.5 V s–1, 1600 rpm, 30 000 cycles). In unit-cell tests, the C-spun electrode achieved an excellent performance of 8.207 W mgPt –1 (H2/air, 80 °C, 1 bar, 100% RH), which is higher than that of the previously reported electrodes with commercial Pt3Co/C. After 50 000 potential scanning cycles, a negligible performance loss was observed. The C-spun electrode provides a new direction for the next-generation electrodes of PEMFCs.

No abstract

With the rapid development of the tourism industry, the water resource consumption in tourism has largely increased and gets more complicated, making water resource management in tourism more difficult. To achieve sustainable water utilization in tourism, water resource management has to take full account of the local natural, social, and industrial conditions, both satisfying the demands of water resource protection and tourism development. To analyze this coupling relationship, an integrated index system comprised of 15 indices is designed, and a coupling degree model between tourism-related water resource management and local conditions is introduced. The result revealed that tourism-related water resource management is generally congruent with the local conditions in China, and provinces at the very high/low coupling stage presented four clusters. A discussion combining the change of water policies and the water use efficiency of hotel in Beijing revealed that water-saving policies are proved to be necessary for the tourism development. Furthermore, a discussion of the four clusters revealed the advanced experience and deficiency of water policies in substantial tourism areas. The results could provide references for the improvement of water policies in the tourism industry in China.