Development of a Wattecs parallel autoclave system synthesis technique for tailoring surface compositions and valence states of Pt-Fe alloys to realize bifunctional electrocatalysis
Development of a Wattecs parallel autoclave system synthesis technique for tailoring surface compositions and valence states of Pt-Fe alloys to realize bifunctional electrocatalysis
复制标题
开发 Wattecs 平行高压釜系统合成技术，用于定制 Pt-Fe 合金的表面成分和价态，以实现双功能电催化
DOI：
10.1039/c7ce01612c
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发表时间：
2017
期刊：
影响因子：
3.1
通讯作者：
Zhang Jun
中科院分区：
文献类型：
--
作者：
Xu Guangran;Liu Jiayin;Liu Baocang;Gong Xia;Wang Shasha;Wang Qin;Zhang Jun
为了促进电化学能量转换和降低燃料电池的成本，迫切需要开发既能用于阳极的甲醇氧化反应（莫尔）又能用于阴极的氧还原反应（ORR）的双功能电催化剂。电催化剂的表面电子构型与表面元素组成和价态有关，在实现双功能和高效电催化方面起着至关重要的作用。在这项研究中，我们证明了双功能Pt-Fe合金电催化剂的实现，有效地催化莫尔和ORR通过定制其表面电子构型通过合成策略，采用Wattecs并联高压釜系统（WPAS），它允许在合成过程中的反应气氛和操作条件的改变，在对比正常的水热方法。优化后的Pt-Fe合金电催化剂具有显著的ORR电催化性能，其半电位（E1/2）为0.9 V（与Ag/AgCl相比），以及稳健的稳定性（3000次循环），并在质量活性为1.82 A mg-1的莫尔比中表现出优异的催化性能，比市售的20%Pt/C（0.23Amg-1）高7.9倍。这些Pt-Fe合金电催化剂还具有长期稳定性和耐受CO中间体的能力，并且由于它们的低成本和上级双功能性（莫尔和ORR）而在可再生能源领域的广泛应用中具有重要意义。Pt-Fe合金电催化剂表面的化学组成和价态的有目的的调制引起的表面电子构型的可变性占电催化性能的增加和在莫尔和ORR中实现双功能催化。
The development of bifunctional electrocatalysts for both the methanol oxidation reaction (MOR) at the anode and the oxygen reduction reaction (ORR) at the cathode is urgently required for promoting electrochemical energy conversion and lowering the cost of fuel cells. The surface electron configuration, correlated to the surface elemental composition and the valence state of an electrocatalyst plays crucial roles in achieving bifunctionality and efficient electrocatalysis. In this study, we demonstrate the achievement of bifunctional Pt–Fe alloy electrocatalysts for effectively catalyzing both the MOR and ORR by tailoring their surface electron configuration via a synthetic strategy employing a Wattecs parallel autoclave system (WPAS), which allows the alteration of reaction atmospheres and operating conditions during the synthetic process, in contrast to a normal hydrothermal method. The optimal Pt–Fe alloy electrocatalyst displayed remarkably enhanced ORR electrocatalytic performance with a half-potential (E1/2) of 0.9 V (vs. Ag/AgCl), together with robust stability (3000 cycles), in the ORR in a 0.1 M HClO4 solution and exhibited excellent catalytic performance in the MOR with a mass activity of 1.82 A mg−1, which is 7.9 times higher than that of commercial 20% Pt/C (0.23 A mg−1). These Pt–Fe alloy electrocatalysts also possessed long-term stability and the ability to tolerate CO intermediates and hold great significance for widespread applications in the field of renewable energy owing to their low cost and superior bifunctionality for both the MOR and ORR. The variability of the surface electron configuration that arose from the purposive modulation of the chemical composition and valence state of the surface of the Pt–Fe alloy electrocatalysts accounted for the increase in electrocatalytic performance and the achievement of bifunctional catalysis in both the MOR and ORR.