掺杂Fe元素对Pd/C催化剂性能的影响

Effect of Adding Fe on the Performances of Pd/C Catalyst

用Fe作为掺杂元素,以活性炭为载体,通过浸溃还原方法制备了Pd:Fe原子比分别为1:1、2:1、1:2的Pd-Fe/C催化剂.采用TEM和XRD技术对合金催化剂的物理性质进行了测试.结果表明,获得的Pd-Fe/C催化剂合金粒子在载体上分布均匀,粒径<5nm,Fe的掺杂量对Pd/C催化剂晶体结构有很大影响,通过电化学性能测试比较,分析了三个不同比例的Pd-Fe/C催化剂和Pd/C催化剂对氢和甲酸的电催化氧化性能.结果得出:在相同的峰值电位下,几种催化剂的电流密度大小顺序为:Pd-Fe/C(1:1)>Pd-Fe/C(2:1)>Pd/C>Pd-Fe/C(1:2).结果表明,适量掺杂Fe提高了Pd/C催化剂的催化性能。且Pd:Fe原子比为1:1时催化性能最好.

Pd-Fe/C catalysts were prepared by the impregnation-reduction method. The ratios of Pd to Fe were 1：1, 2：1, 1：2, respectively. The catalysts were characterized by transmission electron microscope （TEM） and powder X-ray diffraction （XRD）. The results indicate that the catalyst particles are homogeneously distributed in the carrier. The average particle sizes are less than 5nm. The influence of adding Fe on Pd/C catalyst crystal structure was also studied. Finally, the activation of Pd-Fe/C catalysts with different Pd/C ratios to the electrocatalytic oxidation of formic acid was investigated. The results show that the catalytic performances of Pd/C catalyst are improved by adding suitable Fe; the catalytic performance of the Pd-Fe/C catalysts reaches the best when the atom ration of Pd：Fe equal to 1：1.