Direct Formation of Metal Layer on Anion Exchange Membrane Using Electroless Deposition Process

Abstract

In this work, a novel electroless deposition process on the anion exchange membrane (AEM) is proposed. AEM surface has a positively charged functional group, which in general do not allow the catalyst particle, such as Pd, to be formed on the surface. Hence, a different strategy from the conventional catalyzation process was required. We found that the sensitization process using Sn-containing solution, which is widely applied in the electroless plating on nonconductive substrates, hindered the Pd particle modification, which hence inhibited the following deposition reaction. Our several experiments and density functional theory analyses suggest that for Pd particle modification, anion in the bath turned out to play a key role. In particular, Cl − provides the sufficiently strong connection between the precursor Pd 2+ and positive functional group of the substrate. This leads to favorable deposition of Pd catalyst particles and metal layer formation on the AEM. Therefore, we conclude that just a single pre-treatment to immerse the AEM films into PdCl 2 /HCl solution is capable to perform electroless plating on it. We applied the novel process to the electrode formation, such as Pt and NiP , on the AEM for hydrogen evolution reaction (HER) as a case study. Both Pt and NiP was successfully formed on the AEM. The electrochemical measurements show that those electrodes are able to serve as the catalytic electrode for HER. The electroless process proposed here opens possibility of the direct metal fabrication on ion exchange membrane surface.

Plating of Ion‐Exchange Membranes: A Molecular Dynamics Study

“…Overall, our simulations highlight the relative difficulty in plating anion‐ rather than cation‐exchange membranes, which has already been pointed out in the literature [ 22 ] and is likely the reason for the paucity of research on plated anion‐exchange membranes. Indeed, anion‐exchange membranes have positive rigid side‐chains that block the motion of positive ions.…”

“…[ 19 ] Not only have anion‐exchange membranes lower stability than cation‐exchange membranes, [ 20,21 ] but also their electroless plating process introduces many more practical challenges that are difficult to overcome. [ 22 ]…”

“…[19] Not only have anion-exchange membranes lower stability than cationexchange membranes, [20,21] but also their electroless plating process introduces many more practical challenges that are difficult to overcome. [22] In this paper, we propose a classical molecular dynamics (MD) framework to analyze the electrode-membrane interface of both cation-and anion-exchange membranes, toward explaining the differences in properties of the plating between these two types of membranes. Our model allows us to probe the composites at the level of single atoms, and gain a microscopic insight into interfacial phenomena that is unachievable with continuum-scale models.…”

“…Our results confirm experimental observations on the difficulty in plating anion-exchange membranes from ref. [22], which might explain why the literature on IPMCs based on this type of membranes is so scarce. The framework built within this study can be utilized to explore different compositions of the electrodes for ion-exchange membranes, thereby providing a versatile computational benchmark for creating new, stable, and high-performance interfaces and flexible electrodes.…”

Electroless Metallization of the Elements: Survey and Progress

“…The Pt films deposited exhibit the low charge transfer resistance required for use as counter electrodes in dye-sensitized solar cells. Homma and co-workers 397 likewise have described the preparation of Pt electrodes exhibiting superior HER electro-catalytic activity using a pH 7 EL Pt bath containing H 2 PtCl 6 , EDTA, and HCOOH reductant operating at 50 °C.…”