Oxygen electrocatalysis in chemical energy conversion and storage technologies

이재영,Beomgyun Jeong,Joey D. Ocon 한국물리학회 2013 Current Applied Physics Vol.13 No.2

Oxygen electrocatalysis that we first defined is considered as the most important phenomenon in almost all electrochemical industries because it is the most sluggish reaction that governs the overall reaction rate in electrochemical cells. In this review, we cover two main areas of oxygenewater electrocatalysis, oxygen reduction to water and oxygen evolution from water. In particular, it aims to provide the readers with an understanding of the critical scientific challenges facing the development of oxygen electrocatalysts, various unique attributes of recent novel catalysts, the latest developments in electrode construction and the outlook for future generation of oxygen electrocatalysts. This review will be of value to both electrochemists and other applied scientists interested in this field of electrocatalysis.

Oxygen electrocatalysis in chemical energy conversion and storage technologies

Lee, J.,Jeong, B.,Ocon, J.D. Elsevier 2013 Current Applied Physics Vol.13 No.2

<P>Oxygen electrocatalysis that we first defined is considered as the most important phenomenon in almost all electrochemical industries because it is the most sluggish reaction that governs the overall reaction rate in electrochemical cells. In this review, we cover two main areas of oxygen-water electrocatalysis, oxygen reduction to water and oxygen evolution from water. In particular, it aims to provide the readers with an understanding of the critical scientific challenges facing the development of oxygen electro-catalysts, various unique attributes of recent novel catalysts, the latest developments in electrode construction and the outlook for future generation of oxygen electrocatalysts. This review will be of value to both electrochemists and other applied scientists interested in this field of electrocatalysis. (c) 2012 Elsevier B.V. All rights reserved.</P>

Metal–organic framework derived nanomaterials for electrocatalysis: recent developments for CO2 and N2 reduction

Singh Chanderpratap,Mukhopadhyay Subhabrata,Hod Idan 나노기술연구협의회 2021 Nano Convergence Vol.8 No.1

In recent years, we are witnessing a substantially growing scientific interest in MOFs and their derived materials in the field of electrocatalysis. MOFs acting as a self-sacrificing template offer various advantages for the synthesis of carbon-rich materials, metal oxides, and metal nanostructures containing graphitic carbon-based materials benefiting from the high surface area, porous structure, and abundance of metal sites and organic functionalities. Yet, despite recent advancement in the field of MOF-derived materials, there are still several significant challenges that should be overcomed, to obtain better control and understanding on the factors determining their chemical, structural and catalytic nature. In this minireview, we will discuss recently reported advances in the development of promising methods and strategies for the construction of functional MOF-derived materials and their application as highly-active electrocatalysts for two important energy-related reactions: nitrogen reduction to produce ammonia, and CO 2 reduction into carbon-based fuels. Moreover, a discussion containing assessments and remarks on the possible future developments of MOF-derived materials toward efficient electrocatalysis is included.

Morphology‐ and composition‐controlled silver‐containing rhodium nanoparticles for the oxygen reduction reaction

Gyu Seop Hwang,Hongje Jang,Yang-Rae Kim,Woojun Shin,Gyeonghye Yim,Jae Hyuk Choi,Young-Kwan Kim 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.11

Rh nanoparticles (RhNPs) have attracted significant attention due to their superiorelectrocatalytic activity in several energy conversion reactions. However,studies relating their morphology and performance are rare. In this study, threetypes of RhNPs, i.e., nanoshells, nanoframes, and porous nanoplates, were synthesizedvia inverse-directional galvanic replacement. The relationship betweenthe performance of the RhNPs at catalyzing the oxygen reduction reaction(ORR) and their morphology was investigated using cyclic voltammetry, linearsweep voltammetry, the Tafel slope, and electrochemical impedance spectroscopy. X-ray photoelectron spectroscopy and X-ray diffraction data revealed thatthe RhNPs contained different Rh/Ag ratios. All the RhNPs exhibited long-termstability under acidic conditions. In particular, nanoshell-structured RhNPsexhibited superior ORR activity as determined from the slope of the Tafel plot,the number of electrons, and the onset potential compared to a commercialRh electrocatalyst and other RhNPs. Evidently, controlling the morphology andcomposition of RhNPs greatly facilitates efficient electrocatalysis.

Contribution of Carbon Dot Nanoparticles in Electrocatalysis: Development in Energy Conversion Process

Jana, Jayasmita,Ngo, Yen-Linh Thi,Chung, Jin Suk,Hur, Seung Hyun The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.3

Modern electrochemical energy devices involve generation and reduction of fuel gases through electrochemical reactions of water splitting, alcohol oxidation, oxygen reduction, etc. Initially, these processes were executed in the presence of noble metal-based catalyst that showed low overpotential and high current density. However, its high cost, unavailability, corrosion and related toxicity limited its application. The search for alternative with high stability, durability, and efficiency led scientists towards carbon nanoparticles supported catalysts which has high surface area, good electrical conductivity, tunable morphology, low cost, ease of synthesis and stability. Carbon nanoparticles are classified into two groups based on morphology, one and zero dimensional particles. Carbon nanoparticles at zero dimension, denoted as carbon dots, are less used carbon support compared to other forms. However, recently carbon dots with improved electronic properties have become popular as catalyst as well as catalyst support. This review focused on the recent advances in electrocatalytic activities of carbon dots. The mechanisms of common electrocatalytic reactions and the role of the catalysts are also discussed. The review also proposed future developments and other research directions to overcome current limitations.

Transition metal (Fe, Co, Ni, and Mn) oxides for oxygen reduction and evolution bifunctional catalysts in alkaline media

Osgood, Hannah,Devaguptapu, Surya V.,Xu, Hui,Cho, Jaephil,Wu, Gang Elsevier 2016 Nano Today Vol.11 No.5

<P><B>Abstract</B></P> <P>In recent years, a large amount of focus has been given to the development of alternative energy sources that are clean and efficient; among these, electrochemical energy holds potential for its compatibility with solar and wind energy, as well as their applications in fuel cells, and metal-air batteries, and water electrolyzers. However, these technologies require the use of highly active and stable catalysts to make these applications feasible. Current catalysts consist of precious metals such as platinum and iridium, which are expensive and block common access to electrochemical energy. Transition metals, and their oxides, serve as a promising alternative to these precious metals. due to their intrinsic activity and sufficient stability in oxidative electrochemical environments. Among wide range of these metals, cobalt, manganese, nickel, and iron, have been extensively explored as bifunctional catalysts, capable of simultaneously catalyzing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for energy storage and conversion. Not only do they show innate electrochemical capabilities, but their structural diversity, as well as their ability to be mixed, doped, and combined with other materials such as graphene, make transition metal oxides a highly attractive subject in electrochemical and materials research. This review serves to summarize the research currently available concerning transition metal oxides, and their applications as a bifunctional catalyst for the utilized fuel cells and rechargeable metal-air batteris in alkaline media. Particularly, oxide synthesis and their structural properties are related to their electrochemical abilities, along with their behavior when introduced to other catalytic materials and dopants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Review transition metal oxide catalyst for electrochemical energy and conversion via O<SUB>2</SUB> electrocatalysis. </LI> <LI> Provide an overview for cobalt, manganese, nickel, and iron oxide catalysts in terms of their synthesis, structure/morphology, and catalytic activity. </LI> <LI> Focus on elucidation of synthesis–structure–activity correlations for metal oxide nanocomposite catalysts. </LI> <LI> Discuss future oxide catalyst approaches to addressing challenges for ORR and OER catalysis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Exploring Rational Design of Single-Atom Electrocatalysts for Efficient Electrochemical Reduction of CO2 to CO

마준희,조진혁,이강원,김수영 한국재료학회 2023 한국재료학회지 Vol.33 No.2

The electrochemical reduction of carbon dioxide (CO2) to value-added products is a remarkable approach for mitigating CO2 emissions caused by the excessive consumption of fossil fuels. However, achieving the electrocatalytic reduction of CO2 still faces some bottlenecks, including the large overpotential, undesirable selectivity, and slow electron transfer kinetics. Various electrocatalysts including metals, metals oxides, alloys, and single-atom catalysts have been widely researched to suppress HER performance, reduce overpotential and enhance the selectivity of CO2RR over the last few decades. Among them, single-atom catalysts (SACs) have attracted a great deal of interest because of their advantages over traditional electrocatalysts such as maximized atomic utilization, tunable coordination environments and unique electronic structures. Herein, we discuss the mechanisms involved in the electroreduction of CO2 to carbon monoxide (CO) and the fundamental concepts related to electrocatalysis. Then, we present an overview of recent advances in the design of high-performance noble and non-noble singleatom catalysts for the CO2 reduction reaction.

High-temperature-treated multiwall carbon nanotubes for hydrogen evolution reaction

Nguyen, Tri Khoa,Bannov, Alexander G.,Popov, Maxim V.,Yun, Jong-Won,Nguyen, Anh Duc,Kim, Yong Soo Elsevier 2018 International journal of hydrogen energy Vol.43 No.13

<P><B>Abstract</B></P> <P>We investigated the hydrogen evolution reaction (HER) properties of multi-wall carbon nanotubes (MWCNTs) treated at extremely high temperature (2600 °C). The heat treatment not only improves the crystallinity of the MWCNTs, but also reduces the carbon-oxygen (CO) bonding as it is replaced by the defect-carbon (<I>sp</I> <SUP>3</SUP> and CH) bonding. These modifications in the heat treated MWCNT structure lead to the increase of electrochemical charge transfer. The heat treatment of MWCNTs in the composite with Pt (MWCNT-Pt composite) further facilitates electrocatalysis. The MWCNTs-Pt composite shows strong enhancement in the HER performance with an onset of overpotential of −0.04 V vs reversible hydrogen electrode and a Tafel slope of 10.9 mV/decade. This performance is indeed better than that of Pt, which is the best working material for HER.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Heat treatment effects to reorder nanotube structures by connecting the broken crystals. </LI> <LI> CO bonding density is reduced and porosity properties are increased after heat treatment. </LI> <LI> Hydrogen evolution reaction (HER) performance is enhanced after heat treatment. </LI> <LI> Charge transfer resistance in HER is strongly decreased after heat treatment. </LI> <LI> Heat-treated MWCNT-Pt composite yields the excellent HER properties. </LI> </UL> </P>

Carbon dioxide conversion into boron/nitrogen dual-doped carbon as an electrode material for oxygen reduction reaction

Lee, Wonhee,Kim, Gi Mihn,Baik, Seoyeon,Lee, Jae W. Elsevier 2016 ELECTROCHIMICA ACTA Vol.210 No.-

<P><B>Abstract</B></P> <P>This study investigates the effect of boron/nitrogen (B/N) dual doping on the electrocatalytic activity for oxygen reduction reaction (ORR) of carbon materials that are derived from gaseous carbon dioxide (CO<SUB>2</SUB>) at 1atm. In the presence of NaBH<SUB>4</SUB>, CO<SUB>2</SUB> was converted to a B-doped carbon material which was further treated with urea at 850°C for N-doping. Through RDE and RRDE measurements, the enhanced ORR activity of the B/N dual-doped carbon was confirmed in terms of both early onset potentials and large current densities. This arose from the existence of B-N related bond and pyridinic N in the carbon network. As the amount of N content increased, the carbon material became more crystalline and the B/N dual doping led to an increase in the electron transfer number of the carbon materials, implying that the ORR occurred through a dominant four-electron transfer pathway. By utilizing the abundant greenhouse gas as a carbon source, this study provides a facile means by which to synthesize B/N dual-doped carbon for enhanced electrocatalysis.</P>

Continuous photocatalytic, electrocatalytic and photo-electrocatalytic degradation of a reactive textile dye for wastewater-treatment processes: Batch, microreactor and scaled-up operation

Luka Suhadolnik,Andrej Pohar,Uroš Novak,Blaž Likozar,Aleš Miheli9c,Miran Ceh 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.72 No.-

Reactive Red 106, a synthetic azo dye, was degraded by means of photocatalysis, electrocatalysis andphoto-electrocatalysis with an immobilized titanium dioxide nanotube catalyst. The plannedfirst part ofthe experiments was carried out inside a photo-electrocatalytic continuous-flow microreactor unit,which was used for the evaluation of the effective decomposition mechanisms, the assessment of theinvestigated degradation kinetics and the transport. The processes were described with a convection–diffusion–reaction mathematical model. Full degradation was achieved under photo-electrocatalyticoperation. The second half of the tests was executed inside a batch-vessel system, consisting of twoseparate compartments. In the anode device partition, an electrode, made of a nanometer-scaled TiO2tubefilm, was placed, whereas a Ti foil was positioned in the cathode’s electrical section. The separationof the electrolytes made it possible to analyze the conversion individually, monitoring the disintegrationof the textile pigment compound in each structural component separately, and studying the changingenvironmental phenomena for either the polarized positive or negative function. Water-based producedchemicals were determined with ultra-high-performance liquid chromatography (UHPLC), coupled withultraviolet–visible (UV–vis) or mass (MS) spectroscopy detectors. The solution was successfullydiscolored (100%) either under engineered microfluidic operation or inside a beaker’s enclosed volume. However, the rate inside the latter was faster, while there were unlike intermediate species formed ineither the anodic or cathodic electrochemical cell. The maximum conversion achieved on the anode sidewas 80% of the initial concentration of the dye, whereas 63% of the dye was degraded on the cathode side. Finally, a scaled-up input configuration was designed for treating larger feedstock capacities.