合金化提高铂在PEMFC氧还原反应中的催化活性

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

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。

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.