Conversion of PtNi alloy from disordered to ordered for enhanced activity and durability in methanol-tolerant oxygen reduction reactions

划算的氧减小反应(ORR ) 的发展有高甲醇忍耐和提高的耐久性的催化剂为直接甲醇燃料房间是高度合乎需要的。这个工作从混乱稳固的溶液集中于 PtNi nanoparticles 的变换到订的金属间化合的混合物。这里，在 ORR 活动，耐久性，和甲醇忍耐的这变换的效果被描绘。X 光检查衍射和传播电子显微镜学结果与高分散和大约 7.6 nm 的一种吝啬的粒子尺寸证实订的 PtNi 金属间化合的 nanoparticles 的形成。展出的 PtNi 金属间化合的 nanoparticles 在纯、包含甲醇的电解质向甲醇容忍的 ORR 提高了集体、特定的活动。在 PtNi 金属间化合的 nanoparticles 上的 0.85 V 的 ORR 的特定的活动比在商业 Pt/C 和比在混乱 PtNi 合金上大的 3 次上大几乎 6 倍。在 5,000 潜力骑车以后，耐久性测试为 PtNi 金属间化合的 nanoparticles 显示了 ORR 活动的最小的损失，而 ORR 活动为混乱 PtNi 合金在 28% 减少了。提高的 methanoltolerant ORR 活动和耐久性可以被归因于相对混乱 PtNi 合金的稳定性比较的订的 PtNi 金属间化合的 nanoparticles 的结构、组合的稳定性，强烈建议 PtNi 金属间化合的 nanoparticles 可以为实际应用用作高度活跃、持久的甲醇容忍的 ORR electrocatalysts。

The development of cost-effective oxygen reduction reaction （ORR） catalysts with a high methanol tolerance and enhanced durability is highly desirable for direct methanol fuel cells. This work focuses on the conversion of PtNi nanoparticles from a disordered solid solution to an ordered intermetallic compound. Here the effect of this conversion on ORR activity, durability, and methanol tolerance are characterized. X-ray diffraction and transmission electron microscopy results confirm the formation of ordered PtNi intermetallic nanoparticles with high dispersion and a mean particle size of about 7.6 nm. The PtNi intermetallic nanoparticles exhibited enhanced mass and specific activities toward the methanol-tolerant ORR in pure and methanol-containing electrolytes. The specific activity of the ORR at 0.85 V on the PtNi intermetallic nanoparticles is almost 6 times greater than on commercial Pt/C and 3 times greater than on disordered PtNi alloy. Durability tests indicated a minimal loss of ORR activity for PtNi intermetallic nanoparticles after 5,000 potential cycles, whereas the ORR activity decreased by 28% for disordered PtNi alloy. The enhanced methanoltolerant ORR activity and durability may be attributed to the structural and compositional stabilities of the ordered PtNi intermetallic nanoparticles compared relative to the stabilities of the disordered PtNi alloy, strongly suggesting that the PtNi intermetallic nanoparticles may serve as highly active and durable methanol-tolerant ORR electrocatalysts for practical applications.