合金化提高铂在PEMFC氧还原反应中的催化活性

用液相沉积-高温合金化法制备了铂基合金催化剂,用能量散射光谱(EDS)、X射线衍射(XRD)技术对催化剂的结构进行了研究,并测试了使用此催化剂的质子交换膜燃料电池(PEMFC)性能,结果表明铂基合金具有面心立方的结构,铂与过渡金属的原子比接近3∶1;制备的催化剂性能优越,具有比纯铂更强的电催化能力,催化剂活性由高到低的顺序是Pt-Cr/C→Pt-Co/C→Pt-Ni/C→Pt/C。讨论了合金元素对催化剂活性的强化作用,认为合金元素的引入减小了Pt-Pt原子间距,降低了Pt的d电子轨道占有率,提高了催化剂的性能。

Enhancing activity of platinum catalysts for PEMFC oxygen reduction reaction by alloying

The platinum based alloy catalysts were prepared by aquous aggradation and high tempreture alloying method. The structure of the catalyst was studied by energy dissemination spectrum(EDS), X-ray diffraction(XRD). And the performances of catalysts in proton exchange membrane fuel cell (PEMFC) were tested. Results show that the platinum based alloy catalysts has a structure of face-center cubic, the atom ratio of platinum and transition metal is closed to 3:1, the prepared catalysts plays better performance than pure platinum, the activity order is Pt-Cr/C>Pt-Co/C>Pt-Ni/C>Pt/C. The effect of transition metal on the enhancement of catalytic activity was discussed. The result shows that the inducing of alloy element shorten the Pt-Pt distance, increases the d-vacancy of Pt, so it improves the performance of the catalysts.