Electrochemical Approach for Advanced Flow Reactors via Additive Manufacturing of High Surface Area Ti‐6Al‐4V Anode

Abstract

Abstract Electrochemical processes use expensive noble metal‐based anodes which limit industrial implementation. In this study, a noble‐metal‐free Ti‐6Al‐4V anode is introduced in an advanced flow reactor. We demonstrate that the 3D additively manufactured electrode can provide a more projected surface area and facilitate anodic reactions under controlled electrolyte conditions. Alkaline NaOH and KOH electrolytes act as anodic electrolytes that are toxic compounds‐free and enable corrosion control. Impedance and voltammetry responses to electrochemical reactions are studied. The electrochemical active surface area of the 4 rods scaffold geometry is 42 times higher than a flat plate anode. Therefore, improved charge transfer is achieved in the flow reactor incorporating the 3D Ti‐6Al‐4V electrode due to the increased surface area and wettability. The structure of almost non‐conductive passivation on a flat plate anode is changed to unstable passivation due to the 3D scaffold structure. This enables effective charge transfer of 911 mA cm−2 at higher potentials up to 5 V for 1.5 m KOH in a non‐flow condition. Furthermore, a 1 m KOH solution delays metal ion dissolution from the anode surface by acting as a corrosion‐controlling medium. 3D Ti‐6Al‐4V is likely to be an affordable alternative anode in alkaline environmentally friendly electrochemical applications.

Keywords

• alkaline electrolysis
• anodic behavior
• dynamic impedance spectroscopy
• 3D printing
• Ti-6Al-4V