【摘要】：直接甲酸燃料電池(DFAFC)由于其高能量密度、甲酸無毒、不易燃燒、運輸方便等優(yōu)點,在近年來已經(jīng)成為研究熱點。DFAFC中,相對于Pt催化劑,陽極Pd催化劑對甲酸氧化的電催化活性要高很多,但其較低的電催化穩(wěn)定性卻成為制約DFAFC商業(yè)化道路的首要因素。因此,改進陽極Pd催化劑的電催化穩(wěn)定性的研究對DFAFC的發(fā)展具有重大意義。本論文研究了不同載體負載的Pd催化劑對甲酸氧化的電催化性能的影響,并主要從兩方面探討影響其性能優(yōu)劣的因素：一方面是研究所制備的催化劑能否成功提高催化甲酸氧化的電催化活性及穩(wěn)定性,另一方面是研究該催化劑能否抑制甲酸自分解。本論文的研究結(jié)果如下： 1、Keggin型錫取代的多金屬氧酸鹽修飾的Pd/C催化劑對甲酸氧化的電催化性能 通過水浴浸泡法在室溫下制備Keggin型多金屬氧酸鹽K7CoⅡW11O39SnⅣOH修飾的Pd/C催化劑(Pd/C-K7催化劑)。實驗發(fā)現(xiàn),與Pd/C催化劑比較,Pd/C-K7催化劑對甲酸氧化的電催化活性和穩(wěn)定性都得到了很大程度的提高。原因可能有：(1)在Pd/C-K7催化劑上吸附的K7CoⅡW11O39SnⅣOH占據(jù)了部分Pd表面的活性位點,降低了COads在催化劑表面的吸附量；(2)吸附的雜多酸陰離子能加快COads等毒化物種的氧化,對COads的去除起到了一定作用；(3)Pd/C-K7催化劑能有效抑制甲酸的自分解從而減少了CO的產(chǎn)生,減緩了毒化作用。 2、不溶性多金屬氧酸鹽TBA7CoⅡW11O39SnⅣOH作為載體負載Pd催化劑對甲酸氧化的電催化性能 將以Co為中心的不溶性多金屬氧酸鹽TBA7Co11W11O39SnⅣOH作為載體,用液相還原法制備了該載體載Pd的催化劑(Pd/TBA7)由于此不溶性多金屬氧酸鹽TBA7CoⅡW11O39SnⅣOH與Pd之間發(fā)生了強烈的相互作用,既降低了COads在Pd/TBA7催化劑上的吸附量,又抑制了甲酸自分解產(chǎn)生CO,減緩了毒化作用,使得Pd/TBA7催化劑對甲酸氧化的電催化活性和穩(wěn)定性均遠遠優(yōu)于Pd/C催化劑。 3、六方氮化硼(h-BN)與C作混合載體負載Pd催化劑對甲酸氧化的電催化性能 通過液相還原法制備了h-BN與活性炭的不同比例負載Pd催化劑：Pd/BN、Pd/(BN)2C1、Pd/(BN)1C2和Pd/C。實驗發(fā)現(xiàn),h-BN和C的質(zhì)量比會影響Pd催化劑對甲酸氧化的電催化性能。當h-BN與C的質(zhì)量比為2時,Pd/(BN)2C1催化劑的電催化活性和穩(wěn)定性均最好。這是因為C和h-BN各有優(yōu)點,催化劑中C含量過高使得h-BN與Pd接觸面積減小,相互作用變?nèi)酰划敶呋瘎┲蠧含量過低時,催化劑的電阻增加,降低了催化劑的催化活性。所以,當h-BN和C混合載體處于一個最佳比例時,才能使催化劑發(fā)揮最好的電催化性能。
[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，

本文編號：2247083