提高直接甲酸燃料电池阳极Pd催化剂电催化性能的研究
发布时间：2018-09-18 06:36
【摘要】：直接甲酸燃料电池(DFAFC)由于其高能量密度、甲酸无毒、不易燃烧、运输方便等优点,在近年来已经成为研究热点。DFAFC中,相对于Pt催化剂,阳极Pd催化剂对甲酸氧化的电催化活性要高很多,但其较低的电催化稳定性却成为制约DFAFC商业化道路的首要因素。因此,改进阳极Pd催化剂的电催化稳定性的研究对DFAFC的发展具有重大意义。本论文研究了不同载体负载的Pd催化剂对甲酸氧化的电催化性能的影响,并主要从两方面探讨影响其性能优劣的因素：一方面是研究所制备的催化剂能否成功提高催化甲酸氧化的电催化活性及稳定性,另一方面是研究该催化剂能否抑制甲酸自分解。本论文的研究结果如下： 1、Keggin型锡取代的多金属氧酸盐修饰的Pd/C催化剂对甲酸氧化的电催化性能 通过水浴浸泡法在室温下制备Keggin型多金属氧酸盐K7CoⅡW11O39SnⅣOH修饰的Pd/C催化剂(Pd/C-K7催化剂)。实验发现,与Pd/C催化剂比较,Pd/C-K7催化剂对甲酸氧化的电催化活性和稳定性都得到了很大程度的提高。原因可能有：(1)在Pd/C-K7催化剂上吸附的K7CoⅡW11O39SnⅣOH占据了部分Pd表面的活性位点,降低了COads在催化剂表面的吸附量；(2)吸附的杂多酸阴离子能加快COads等毒化物种的氧化,对COads的去除起到了一定作用；(3)Pd/C-K7催化剂能有效抑制甲酸的自分解从而减少了CO的产生,减缓了毒化作用。 2、不溶性多金属氧酸盐TBA7CoⅡW11O39SnⅣOH作为载体负载Pd催化剂对甲酸氧化的电催化性能 将以Co为中心的不溶性多金属氧酸盐TBA7Co11W11O39SnⅣOH作为载体,用液相还原法制备了该载体载Pd的催化剂(Pd/TBA7)由于此不溶性多金属氧酸盐TBA7CoⅡW11O39SnⅣOH与Pd之间发生了强烈的相互作用,既降低了COads在Pd/TBA7催化剂上的吸附量,又抑制了甲酸自分解产生CO,减缓了毒化作用,使得Pd/TBA7催化剂对甲酸氧化的电催化活性和稳定性均远远优于Pd/C催化剂。 3、六方氮化硼(h-BN)与C作混合载体负载Pd催化剂对甲酸氧化的电催化性能 通过液相还原法制备了h-BN与活性炭的不同比例负载Pd催化剂：Pd/BN、Pd/(BN)2C1、Pd/(BN)1C2和Pd/C。实验发现,h-BN和C的质量比会影响Pd催化剂对甲酸氧化的电催化性能。当h-BN与C的质量比为2时,Pd/(BN)2C1催化剂的电催化活性和稳定性均最好。这是因为C和h-BN各有优点,催化剂中C含量过高使得h-BN与Pd接触面积减小,相互作用变弱；当催化剂中C含量过低时,催化剂的电阻增加,降低了催化剂的催化活性。所以,当h-BN和C混合载体处于一个最佳比例时,才能使催化剂发挥最好的电催化性能。
[Abstract]:Because of its high energy density, non-toxic formic acid, non-flammable, convenient transportation and other advantages, direct formic acid fuel cell (DFAFC) has become a research hotspot in recent years, compared with Pt catalyst. The electrocatalytic activity of anodic Pd catalyst for formic acid oxidation is much higher, but its low electrocatalytic stability has become the primary factor restricting the commercialization of DFAFC. Therefore, it is of great significance to improve the electrocatalytic stability of anodic Pd catalysts for the development of DFAFC. In this paper, the effect of Pd catalysts supported on different supports on the electrocatalytic performance of formic acid oxidation was studied. The main factors affecting its performance are as follows: one is whether the catalyst prepared by the Institute can improve the catalytic activity and stability of formic acid oxidation, and the other is whether the catalyst can inhibit the self-decomposition of formic acid. The results of this thesis are as follows: 1. The electrocatalytic properties of Pd/C catalysts modified with Keggin tin for formic acid oxidation were prepared at room temperature by water bath immersion method. Acid salt K7Co 鈪，
本文编号：2247083
[Abstract]:Because of its high energy density, non-toxic formic acid, non-flammable, convenient transportation and other advantages, direct formic acid fuel cell (DFAFC) has become a research hotspot in recent years, compared with Pt catalyst. The electrocatalytic activity of anodic Pd catalyst for formic acid oxidation is much higher, but its low electrocatalytic stability has become the primary factor restricting the commercialization of DFAFC. Therefore, it is of great significance to improve the electrocatalytic stability of anodic Pd catalysts for the development of DFAFC. In this paper, the effect of Pd catalysts supported on different supports on the electrocatalytic performance of formic acid oxidation was studied. The main factors affecting its performance are as follows: one is whether the catalyst prepared by the Institute can improve the catalytic activity and stability of formic acid oxidation, and the other is whether the catalyst can inhibit the self-decomposition of formic acid. The results of this thesis are as follows: 1. The electrocatalytic properties of Pd/C catalysts modified with Keggin tin for formic acid oxidation were prepared at room temperature by water bath immersion method. Acid salt K7Co 鈪，
本文编号：2247083
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