Palladium ions (e.g., $\ce{Pd^2+}$) can be reduced to $\ce{Pd}$ by more reactive metals such as zinc. Metal oxides such as $\ce{ZnO}$ are very stable but can its atoms in the oxide structure still be displaced by Pd? I know the answer is probably "No" but in one of my samples $\ce{ZnO}$ nanoparticles were removed from the solution after I added $\ce{Pd^2+}$ solution to the system and $\ce{Pd}$ nanoparticles were formed. The solvent was methanol. After washing the solution and drying I did XPS and no trace of zinc was observed but saw $\ce{Pd}$ peaks.

  • $\begingroup$ The metals aren’t connected to the Swedish entrepreneur Alfred Nobel but to the English adjective to nobility: noble. As for the actual question, I sadly cannot give you an answer. $\endgroup$ – Jan Dec 16 '18 at 17:02
  • $\begingroup$ Did you measure the size of the nano-particles? According to Wikipedia, at most, the XPS instrument will only probe $\pu{20 nm}$ into a sample. Thus, I wonder, $\ce{Pd}$ has been deposited on $\ce{ZnO}$ surface. "Palladium Deposition on $\ce{Pt}$ Surface by Reduction of $\ce{Pd^2+}$ Ions with Organic Substances" has been studied before (link.springer.com/article/10.1023/A:1010314807520). $\endgroup$ – Mathew Mahindaratne Dec 16 '18 at 22:44

Zinc chemistry is overwhelmingly that of the +2 oxidation state, it does not go higher. For ZnO to reduce Pd+2, the Zn has to go up from +2 which it cannot. If you are getting reduction of Pd+2, Zn is not responsible.

  • $\begingroup$ Perhaps ZnO is catalyzing the reduction of Pd(II) to Pd(0) with methanol as the reducing agent (oxidized to formaldehyde). I presume the Pd(II) is stable in methanol. $\endgroup$ – user55119 Dec 16 '18 at 23:43

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.