Electrochemical Synthesis of a Multipurpose Pt−Ni Catalyst for Renewable Energy‐Related Electrocatalytic Reactions. Issue 21 (2nd November 2020)

• Record Type: Journal Article
• Authors: Abu Sayeed, Md; Woods, Charlotte; Love, Jonathan; O'Mullane, Anthony P.
• Is Part Of: ChemElectroChem. Volume 7:Issue 21(2020)
• Page Start: 4369
• Page End: 4377
• Publication Date: 2020-11-02
• Subjects: water splitting -- electrocatalysis -- Pt−Ni alloy -- ORR -- ammonia oxidation; Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.202001278
• Languages: English
• ISSNs: 2196-0216

Abstract

Abstract: Renewable energy driven electrochemical processes are becoming increasingly important in the transition away from fossil fuels. One of the key reactions is electrochemical water splitting to generate green hydrogen which ideally could be directly integrated with a wind or solar electricity source. However, alkaline electrolysers suffer from significant degradation in performance if they are rapidly powered down under reduced sunlight conditions when directly coupled with a solar cell due to reverse current flow. In this work we address this issue by creating a truly bifunctional electrode material that is switchable between the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The synthesis method is simple whereby a Pt electrode is electrochemically activated and then immersed in a nickel nitrate solution to electrolessly deposit Ni on the surface. When this electrode is electrochemically cycled, it creates an active Pt−Ni alloy at the Pt surface. Importantly, this electrocatalyst is switchable between both reactions without loss of activity as evidenced by an accelerated stress test over a 24 h period. An added advantage is that this Pt−Ni electrocatalyst is also more active than Pt for the oxygen reduction reaction which opens up its applicability in fuel cells. Finally, to demonstrate the multifunctionality of this Pt−Ni material, ethanol and ammonia oxidation is demonstrated which also shows better performance than Pt. Abstract : One for all : The electrochemical synthesis of a Pt−Ni electrode is achieved via a simple activation/electroless deposition process to create Pt3 Ni alloys on the surface of a Pt electrode. This electrocatalyst demonstrates bifunctional behaviour for overall water splitting while also being active for fuel cell relevant reactions such as the oxygen reduction reaction and ammonia oxidation.