炭载Pd-Fe合金催化剂的制备及电催化氧还原活性

Carbon Supported Alloy Pd-Fe Catalyst:Preperation and Electrocatalytic Activity for Oxygen Reduction

研究了用NH4Cl作配位剂的配位还原法来制备的Pd-Fe/C催化剂,发现由于NH4Cl能与Pd形成配合物,使Pd Cl2的还原电位负移,与Fe Cl3的还原电位接近,从而在低温下制备得到了高合金化程度的Pd-Fe/C催化剂。XPS表征结果表明:Pd与Fe形成合金后,Pd的电荷密度的减少,增加了Pd0的含量。因此,得到的Pd-Fe/C催化剂对氧还原的电催化活性比用相同方法制得的Pd/C催化剂高,而且该催化剂对甲醇氧化没有电催化活性。

The Pd-Fe/C catalyst was prepared by the complexing reduction method using NH4 Cl as the complex agent at the low temperature.The high alloy Pd-Fe/C catalyst Pd and Fe could be prepared at low temperature due to the complex formation by NH4 Cl and Pd,which leads to a negative shift for the reduction potential of Pd Cl2,making the reduction potential of Pd Cl2 closer to that of Fe Cl3.The XPS results show that the alloying of Pd with Fe could affect the binding energies of Pd and increase the content of Pd^0 in the catalyst.Thus,the electrocatalytic activity of the Pd-Fe/C catalyst obtained for the oxygen reduction is higher than that of the Pd/C catalyst prepared with the same method.Furthermore,this Pd-Fe/C catalyst has no electrocatalytic activity for the methanol oxidation.