Recent progress in Pt-based electrocatalysts for ammonia oxidation reaction. (December 2022)

• Record Type: Journal Article
• Authors: Kim, Hyunki; Hong, Seokjin; Kim, Hedam; Jun, Yeji; Kim, Soo Young; Ahn, Sang Hyun
• Is Part Of: Applied materials today. Volume 29(2022)
• Publication Date: 2022-12
• Subjects: Hydrogen economy -- Electrochemical ammonia oxidation reaction -- Direct ammonia fuel cell -- Ammonia electrolysis cell -- Pt-based catalyst; AOR ammonia oxidation reaction -- AEC ammonia electrolysis cell -- DAFC direct ammonia fuel cells -- DEMS differential electrochemical mass spectroscopy -- SERS surface-enhanced Raman spectroscopy -- CV cyclic voltammetry -- HUPD hydrogen underpotential deposition -- HRTEM high-resolution transmission electron microscopy -- fcc face-centered cubic -- SCE saturated calomel electrode -- NCs nanocubes -- XRD X-ray powder diffraction -- RDE rotating disk electrode -- RHE reversible hydrogen electrode -- w/o water-in-oil -- HER hydrogen evolution reaction -- ECSA electrochemical surface area -- FFT fast Fourier transform -- FTIR Fourier-transform infrared -- OCV open-circuit voltage -- ITO indium tin oxide -- EL lower potential limit -- CP chronopotentiometry -- Ea activation energy -- GC gas chromatography -- FE Faraday efficiency -- OER oxygen evolution reaction -- MEA membrane electrode assembly -- CuUPD Cu underpotential deposition -- DFT density functional theory -- RO rare earth oxide -- ATR-IR attenuated total reflection infrared -- HCOND hyperbranched concave octahedron -- ADT accelerated durability test ADT -- ZIF-8 zeolitic imidazolate framework-8; Materials science -- Periodicals; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1016/j.apmt.2022.101640
• Languages: English
• ISSNs: 2352-9407

Abstract

Highlights: Pt-based electrocatalysts for the ammonia oxidation reaction are summarized. Recent progress in application of Pt-based anodes is presented. Strategies to catalyst design for high activity and stability is introduced. Remaining challenges and future research are suggested. Abstract: Ammonia oxidation reaction (AOR) has attracted great interest in the context of electrocatalytic hydrogen generation and direct fuel generation. Owing to its low theoretical cell voltage, the ammonia oxidation electrode is considered a promising anode candidate for electrical energy conversion systems. However, its low kinetics causes a high overpotential and results in a loss of cell efficiency. Pt is well known as the best AOR catalyst, and Pt-based catalysts have been mainly studied. Pt-free catalysts have also been reported, but they exhibit insufficient performance compared to Pt-based catalysts. In this review, we briefly discuss the advantages of ammonia fuel and its promising applications in energy-conversion systems. Although the AOR mechanism remains controversial, most experimental studies and theoretical calculations have been conducted on Pt catalysts. We highlight recent progress in electrical ammonia oxidation electrodes based on the fundamentals of the AOR mechanism. In particular, we focus on designing a strategy for achieving high AOR activity and its application to ammonia electrolysis cells and direct ammonia fuel cells. Finally, prospective directions for the study of AOR catalysts and practical devices were discussed. Graphical abstract: Image, graphical abstract