研究在柠檬酸钾和草酸铵镀液体系中纯钯电沉积及电结晶机理．结果表明，采用本实验室研制的添加剂②ＸＰ－４和ＸＰ－７，可在电流密度０．５～３．５Ａ／ｄｍ２，温度４０～６０℃的宽广范围内获得全光亮的钯电沉积积层．采用脉冲电源电镀可有效地改善厚沉积层质量，减少沉积层裂纹和孔洞．循环伏安实验表明，钯电极过程的阴阳极峰电位之差达１．０５Ｖ，说明其电极过程明显不可逆；伏安图上同时出现一感抗性电流环，说明钯沉积过程发生晶核形成过程；ＸＰ－４和ＸＰ－７阻化电沉积和氢的析出，提高钯电沉积的沉积电位．电位阶跃实验进一步表明，钯遵循连续成核和三－维生长的电结晶机理．
The electrodeposition and nucleation of palladium are studied in the system of potassium citrate and ammonium oxalate. The results show that, with the additives of XP 4 and XP 7 prepared in our laboratory, a full bright palladium electrodeposits will be obtained in the wide ranges of the cathode current densities 0.5～3.5 A/dm 2 and temperature 40～60 ℃; the qualities of the thick deposits will be effectively improved by means of pulse current plating. Cyclic voltammograms results show that the division of peaks between anodic and cathodic on the electrode process of palladium will be up to 1.05 V, which shows the irreversible electrode process; and a inductive current cycle is appeared,which means the process of nucleation; XP 4 and XP 7 inhibit both palladium electrodeposition and hydrogen evolution, therefore cause the deposition potential of palladium to more negative; potential step experiments furtherly show that the nucleation of palladium obeyed progressive uncleation mechanism both with the studied additives or without them.
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