直接乙醇燃料电池阳极催化剂Pt-CeO_2/C的制备与性能表征

Preparation and Characterization of Pt-CeO_2/C as Catalyst for Direct Ethanol Fuel Cell

用水热合成法,以葡萄糖为原料在不添加有机物模板剂的前提下,制备了尺寸可控的中空碳球为催化剂载体,加入自制的孔径在30~40nm范围内,比表面积为126m^2/g的花状CeO_2为助剂,用微波辅助乙二醇还原氯铂酸法合成了催化剂。利用扫描电镜(SEM)、透射电镜(TEM)、红外光谱(IR)、X射线衍射(XRD)、比表面(BET)对所制备的载体及助剂进行了表征,利用电化学工作站对所制备的催化剂进行了电化学性能测试。表征结果为,所制备的碳球粒径分布的范围是0.4~0.9μm,表面含有-OH,-C=O,-COOH含氧官能基。电化学测试表征结果为,添加了花状CeO_2的Pt-CeO_2/C催化剂的催化性能,稳定性和抗中毒能力比传统的Pt/C更优秀。随着碳球载体粒径的减小,催化剂的催化性能,稳定性及抗中毒能力随之增强。葡萄糖浓度为0.5mol/L,水热反应时间为4h条件下合成的碳球作载体,并加入花状CeO_2为助剂合成的催化剂对乙醇的催化氧化具有最佳的活性、稳定性及抗中毒能力。

Size controllable hollow carbon spheres used as catalyst carrier were prepared by hydrothermal synthesis with glucose as the raw material without adding organic template, the self-made flower-like CeO2 with a pore size in the range of 30 - 40 nm and a specific surface area of 126 mZ/g was added as auxiliary catalyst, and a catalyst was prepared by microwave-assisted reduction of chloroplatinic acid with ethylene glycol. The prepared catalyst carrier and auxiliary catalyst were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, infrared spectroscopy （IR）, X-ray diffraction （XRD） and specific surface area （BET）. The electrochemical performance of the prepared catalyst was tested by electrochemical workstation. The results show that the size distribution of the carbon spheres is between 0.4 and 0.9 ~tm and the surface contains -OH, -C=O, -COOH oxygen-containing functional groups. The results of electrochemical tests show that compared with the traditional Pt/C catalyst, Pt-CeO2/C catalyst with the addition of flower-like CeO2 has better catalytic activity, stability and anti-CO poisoning capacity. With the decrease of the size of the carbon sphere carrier, the catalytic performance, stability and anti-CO poisoning ability of the catalyst is enhanced. The catalyst, using the carbon spheres prepared under the condition of glucose concentration of 0.5 mol/L and hydrothermal reaction time of 4 h as the carrier and the floral CeO2 as the auxiliary catalyst, has the best activity, stability and anti-CO poisoning capacity for the catalytic oxidation of ethanol.