电解液对炭载Pd催化剂对甲酸氧化的电催化性能的影响

摘要

In order to understand the effect of (NH4)2SO4,K2SO4 and H2SO4 electrolytes on the electrocatalytic performance and the mechanisim of the Pd/C catalyst electrode for formic acid oxidation, the performance of the said electrode for formic acid oxidation in different electrolytes were evaluated using electrochemical methods. The results show that the electrocatalytic activity and stability are decreased according to the following order: (NH4)2SO4＞ K2SO4＞H2SO4. Because of the existence of formic acid, the difference in the pH value of different electrolytes is small. Thus, the effect of the pH value of the electrolytes is small. Moreover, the conductivity of the electrolytes would affect the peak potential of the formic acid oxidation. Finally, NH4+ plays a special rule. It could decrease the amount of CO adsorbed on the Pd/C catalyst. The electrocatalytic performance of the Pd/C catalyst for formic acid oxidation in (NH4)2SO4 electrolyte is the best among three electrolytes.%为了了解(NH4)2SO4,K2SO4和H2SO4电解液对炭载Pd(Pd/C)催化剂对甲酸氧化的电催化性能的影响和机理,用电化学方法测量了Pd/C催化剂在不同电解液中对甲酸氧化的电催化性能.发现在不同电解液中,Pd/C催化剂对甲酸氧化的电催化活性和稳定性按(N H4)2SO4＞K2SO4＞H2SO4的次序降低.由于在含甲酸的电解液中,不同电解液的pH值差别较小,电解液的pH值只有较小的影响.其次,电解液的电导率对甲酸氧化峰峰电位有一定的影响.最后,由于NH+4起着特殊作用,它能降低CO在Pd/C催化剂电极上的吸附量,因此,在(NH4)2SO4电解液中,Pd/C催化剂对甲酸氧化的电催化性能最好.