摘要
Sluggish kinetics of anodic hydrogen oxidation reaction(HOR)in alkaline media,which arises from the two orders of magnitude lower HOR activity in alkali than that in acid media for platinum group metals,hinders the commercial implementation of anion exchange membrane fuel cells(AEMFCs).Consequently,the development of platinum-based catalysts combined with high efficiency and durability is urgently required.Herein,we report a facile route for the synthesis of ternary PtRuTe alloy nanofibers with Pt atomic ratio of only 11%via a simple galvanic replacement reaction.We optimize the adsorption strength of platinum and ruthenium towards hydrogen and hydroxyl species by regulating the electron donation from tellurium to platinum and ruthenium.Hence,the obtained trimetallic alloy catalyst exhibits an impressive kinetic current density of 30.6 mA cm^(−2)_(geo) at 50 mV and an exchange current density of 0.426 mA cm^(−2)_(metal),which shows 3.0-and 2.5-fold enhancement compared with the commercial Pt/C in alkaline electrolyte,respectively.Moreover,the catalyst also demonstrates excellent stability with merely 5%activity attenuation after 2000 potential cycles.This work offers new pathways to boost alkaline HOR by rationally designing multicomponent alloys.
由于金属铂在碱性介质中针对氢气氧化反应的电催化活性比酸性介质中低两个数量级,阳极上缓慢的反应动力学不利于阴离子交换膜燃料电池的商业化.因此,发展高效且稳定的铂基催化剂显得十分迫切.我们在本文中报道了一种电置换反应合成铂原子比仅为11%的三元PtRuTe合金纳米纤维的简易方法.通过调节碲对铂和钌的电子贡献可以优化表面铂和钌原子与氢和羟基物质之间的吸附强度.基于此,该PtRuTe催化剂的动力学电流密度和交换电流密度在50 mV(相比于可逆氢电极)时达到了30.6 mA cm^(−2)_(geo)和0.426 mA cm^(−2)_(metal),分别是碱性介质中商业Pt/C催化剂活性的3倍和2.5倍.此外,PtRuTe催化剂在2000次电势循环后活性仅衰减5%,展现出了优异的稳定性.本研究可为合理设计多元合金以提高碱性介质中氢气氧化电催化效率提供参考.
基金
the National Natural Science Foundation of China(21905178)
Shenzhen Science and Technology Program(JCYJ20190808143007479 and JCYJ20170818144659020).
