(1. 華東理工大學(xué) 機(jī)械與動(dòng)力工程學(xué)院，上海 200237；
2. 上海交通大學(xué) 燃料電池研究所，上海 200240)
摘 要: 采用濕化學(xué)法研究還原劑甲酸濃度對(duì)鉑納米線(Pt-NWs)長(zhǎng)度和分布的影響以及Pt-NWs對(duì)單電池的電化學(xué)性能和耐久性的影響。結(jié)果表明：隨著還原劑濃度的增加(0.075~0.590 mol/L)，Pt-NWs的長(zhǎng)度先增加后減小，在碳基體層厚度方向上Pt分布從均勻到逐漸聚集在表層，呈現(xiàn)明顯梯度特征。當(dāng)還原劑濃度為0.372 mol/L時(shí)，可獲得在整個(gè)碳基體層厚度方向上分布的Pt-NWs團(tuán)簇，與商用的催化劑(JM Pt/C)相比，在0.6 V時(shí)，電流密度提高11.3%，最大功率密度提高12.5%，這主要?dú)w于Pt-NWs的一維結(jié)構(gòu)、在催化層中的梯度分布以及高Pt利用率。通過(guò)加速耐久性測(cè)試，Pt-NWs/C的最大功率密度和電化學(xué)活性表面積比JM Pt/C的衰減緩慢，說(shuō)明Pt-NWs/C具有更好的穩(wěn)定性。
關(guān)鍵字: 鉑納米線；原位沉積；還原劑濃度；質(zhì)子交換膜燃料電池
（1. School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China;
2. Institute of Fuel Cells, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:The effects of reducing agent formic acid concentrations on the length and distribution of platinum nanowires (Pt-NWs) and the electrochemical performance and durability of single cells were investigated. The results show that, with the increase of reducing agent concentration (0.075-0.590 mol/L), the length of Pt-NWs increases firstly and then decreases, meanwhile, the distribution of Pt-NWs through thickness direction of the carbon-based layer is from uniform distribution to obvious gradient distribution with gradual aggregation. The Pt-NWs clusters uniformly distribute on the carbon surface are obtained at a reducing agent concentration of 0.372 mol/L. Compared with JM Pt/C, the current density of the Pt-NWs clusters used as the cathode of PEMFC increases by 11.3% at 0.6 V and the maximum power density increases by 12.5%. The improvement of the performance of the Pt-NWs catalytic layer is mainly attributed to the one-dimensional structure of Pt-NWs, the gradient distribution in the catalytic layer, and the high Pt utilization. By 5000 cycles accelerating durability test, the performance degradation of Pt-NWs/C is slower than that of JM Pt/C, indicating its better stability than that of the later. The optimized platinum nanowire catalytic layer obtained promotes the design of novel nanostructures in practical applications.
Key words: Pt nanowires; in-situ deposition; reducing agent concentration; proton exchange membrane fuel cell (PEMFC)
