{"title":"Electrocatalytic ethanol-to-CO2 selectivity on the Ir electrode: A quasi-quantitative electrochemical infrared absorption spectroscopic investigation","authors":"Rui-Lin Wei , Yue Liu , Yao-Yue Yang","doi":"10.1016/j.apcatb.2023.123638","DOIUrl":null,"url":null,"abstract":"<div><p>Ir has long been regarded as an alternative ethanol-to-CO<sub>2</sub><span> electrocatalyst, but little is known about the ethanol oxidation reaction (EOR) mechanism on Ir, especially the C1 pathway selectivity. Thereby, in situ quasi-quantitative electrochemical infrared absorption spectroscopy (QEIAS), consisting of total-reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), infrared absorption spectroscopy (IRAS), and transmission infrared absorption spectroscopy (TIAS) with a thin-layer flow cell, is established to probe it. Initially, the well-accepted EOR dual-pathway mechanism is confirmed via ATR-SEIRAS and IRAS. Ir-H</span><sub>ad</sub> species (ca. 2040 cm<sup>−1</sup>), originating from the ethanol dissociation at low potentials, are observed for the first time to replenish the reaction process. Based on it, the apparent Faradaic efficiency of the C1 pathway (<em>FE</em><sub>C1</sub>) is readily estimated to be as high as 76.4% (0.7 V) in acidic media. The quantitative analysis of reaction residual verifies these <em>FE</em><sub>C1</sub> results through high-performance liquid chromatography (HPLC), and a relative error of only 2–9% exists between the two methods. Thus, Ir might be more efficient for ethanol complete oxidation than other Pt-group metallic catalysts, especially in acidic media. This work could be necessary for the rational design of Ir-based EOR catalysts with high C1 pathway selectivity and low over-potential for direct ethanol fuel cells.</p></div>","PeriodicalId":244,"journal":{"name":"Applied Catalysis B: Environmental","volume":"344 ","pages":"Article 123638"},"PeriodicalIF":21.1000,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Catalysis B: Environmental","FirstCategoryId":"1","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S092633732301281X","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Ir has long been regarded as an alternative ethanol-to-CO2 electrocatalyst, but little is known about the ethanol oxidation reaction (EOR) mechanism on Ir, especially the C1 pathway selectivity. Thereby, in situ quasi-quantitative electrochemical infrared absorption spectroscopy (QEIAS), consisting of total-reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), infrared absorption spectroscopy (IRAS), and transmission infrared absorption spectroscopy (TIAS) with a thin-layer flow cell, is established to probe it. Initially, the well-accepted EOR dual-pathway mechanism is confirmed via ATR-SEIRAS and IRAS. Ir-Had species (ca. 2040 cm−1), originating from the ethanol dissociation at low potentials, are observed for the first time to replenish the reaction process. Based on it, the apparent Faradaic efficiency of the C1 pathway (FEC1) is readily estimated to be as high as 76.4% (0.7 V) in acidic media. The quantitative analysis of reaction residual verifies these FEC1 results through high-performance liquid chromatography (HPLC), and a relative error of only 2–9% exists between the two methods. Thus, Ir might be more efficient for ethanol complete oxidation than other Pt-group metallic catalysts, especially in acidic media. This work could be necessary for the rational design of Ir-based EOR catalysts with high C1 pathway selectivity and low over-potential for direct ethanol fuel cells.
期刊介绍：
Applied Catalysis B: Environment and Energy (formerly Applied Catalysis B: Environmental) is a journal that focuses on the transition towards cleaner and more sustainable energy sources. The journal's publications cover a wide range of topics, including:
1.Catalytic elimination of environmental pollutants such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, and soot emitted from stationary or mobile sources.
2.Basic understanding of catalysts used in environmental pollution abatement, particularly in industrial processes.
3.All aspects of preparation, characterization, activation, deactivation, and regeneration of novel and commercially applicable environmental catalysts.
4.New catalytic routes and processes for the production of clean energy, such as hydrogen generation via catalytic fuel processing, and new catalysts and electrocatalysts for fuel cells.
5.Catalytic reactions that convert wastes into useful products.
6.Clean manufacturing techniques that replace toxic chemicals with environmentally friendly catalysts.
7.Scientific aspects of photocatalytic processes and a basic understanding of photocatalysts as applied to environmental problems.
8.New catalytic combustion technologies and catalysts.
9.New catalytic non-enzymatic transformations of biomass components.
The journal is abstracted and indexed in API Abstracts, Research Alert, Chemical Abstracts, Web of Science, Theoretical Chemical Engineering Abstracts, Engineering, Technology & Applied Sciences, and others.
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