Hydrogen production from water electrolysis: role of catalysts

Wang Shan,Lu Aolin,Zhong Chuan-Jian 나노기술연구협의회 2021 Nano Convergence Vol.8 No.4

As a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.

전기화학적 수소발생반응을 위한 카본 페이퍼 위 NiCoS의 펄스 전기전착

임소연(Soyeon Lim),임태호(Taeho Lim) 한국세라믹학회 2022 세라미스트 Vol.25 No.2

NiCoS has good conductivity, and the sulfur it contains is known to improve the activity for hydrogen evolution reaction. Thus NiCoS has recently attracted much attention as a catalyst for hydrogen evolution reaction catalyst in neutral-pH water electrolysis. In this study, NiCoS was fabricated using pulse electrodeposition method and the effect of off time on the composition, morphology, and hydrogen evolution reaction activity was investigated. The physical and chemical characteristics of the catalyst were analyzed using field emission scanning electron microscopy, X-ray diffractometry, electrochemical impedance spectroscopy, etc. It was observed that the surface area of NiCoS, the sulfur content, and hydrogen evolution reaction activity of NiCoS increased together as the off time increased at a constant on time. The NiCoS with the highest sulfur content, produced by pulse electrodeposition, showed overpotentials of 262 and 285 mV to deliver current densities of 10, 50 mA/cm2, respectively, in the neutral pH region.

Mechanism in pH effects of electrochemical reactions: a mini-review

Liu Sibei,Wang Zhuowen,Qiu Shan,Deng Fengxia 한국탄소학회 2024 Carbon Letters Vol.34 No.5

pH plays a pivotal role in influencing various aspects of proton-coupled electron transfer (PCET) reactions in electrochemical systems. These reactions are affected by pH in terms of mass transport, electrochemical double layer (EDL) structure, and surface adsorption energy, all of which impact the overall electrochemical processes. This review article aims to provide a comprehensive understanding of the research progress made in elucidating the effects of pH on different electrochemical reactions, the hydrogen evolution reaction/hydrogen oxidation reaction (HER/HOR), oxygen reduction reaction/oxygen evolution reaction (ORR/OER), and carbon dioxide reduction reaction (CO2RR). To embark on this endeavor, we have conducted a bibliometric analysis to clearly outline of the research trends and advancements in the field concerning the pH effects. Subsequently, we present a systematic overview of the mechanisms governing these reactions, with a special focus on pH’s influence on both the proton and electron aspects. We conclude by discussing the current challenges in this area and suggesting future research avenues that could further our understanding of pH's role in electrochemical reactions.

Design of active bifunctional electrocatalysts using single atom doped transition metal dichalcogenides

Hwang, Jeemin,Noh, Seung Hyo,Han, Byungchan Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.471 No.-

<P><B>Abstract</B></P> <P>Single atom catalyst is designed to achieve high catalytic activity while extremely minimizing precious metal loadings for electrochemical energy conversion and storage applications. Using first-principles density functional theory calculations, we screen 48 combinations of single atom catalysts anchored at defective monolayer transition metal dichalcogenides (A<SUB>1</SUB>/TMD; A = Ni, Cu, Pd, Ag, Pt and Au; TM = Mo, W, Nb and Ta; D = S and Se). With established methodologies, we identify five best catalysts for each of oxygen reduction/evolution and hydrogen evolution reactions among the stable candidates. A scaling relation between the Gibb’s free energy for intermediates is figured out to understand the governing mechanism of single atom catalysts with varying transition metal dichalcogenides supports and to introduce key descriptor. Pt<SUB>1</SUB>/MoS<SUB>2</SUB> is proposed as the best bifunctional catalyst for oxygen reduction/evolution reaction. In addition, Pt<SUB>1</SUB>/NbSe<SUB>2</SUB> and Pt<SUB>1</SUB>/TaS<SUB>2</SUB> are promising candidates for oxygen and hydrogen evolution reactions. Treating the support itself as an active site for hydrogen evolution reaction, Pd<SUB>1</SUB>/NbS<SUB>2</SUB> and Pt<SUB>1</SUB>/NbS<SUB>2</SUB> are proposed as potential bifunctional catalysts toward oxygen reduction and evolution reaction, respectively. Conceptual design principle via high-throughput screening of single atom catalyst is demonstrated as a great approach to determine active and durable bifunctional single atom catalysts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Single atom catalysts with transition metal dichalcogenides supports were screened. </LI> <LI> Five best catalysts were selected for redox reactions of oxygen and hydrogen. </LI> <LI> Pt<SUB>1</SUB>/MoS<SUB>2</SUB> was identified as a great bifunctional single atom catalyst. </LI> <LI> Scaling law was proposed as the key to understand catalytic mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Phase transformation of iron phosphide nanoparticles for hydrogen evolution reaction electrocatalysis

Cho, Geonhee,Kim, Hoyoung,Park, Yoon Su,Hong, Yun-Kun,Ha, Don-Hyung Elsevier 2018 International journal of hydrogen energy Vol.43 No.24

<P><B>Abstract</B></P> <P>Transition metal phosphides have emerged as alternative electrocatalysts for hydrogen evolution reaction (HER) due to their high activity and low cost compared to the conventional HER electrocatalysts such as Pt. However, the dependency of HER activity on different crystal phases is not well-understood. Here, we synthesized iron phosphide nanoparticles with two distinct phases via chemical transformation from iron metal to iron phosphides. During the development of iron phosphide phases by varying the synthesis conditions such as reaction temperature and time, the HER activities of the nanoparticle were examined. The HER activities of the iron phosphide nanoparticles were found to be phase-dependent.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two phases of iron phosphide nanoparticles (NPs) were synthesized from iron NPs. </LI> <LI> XRD, TEM, and XPS were used to analyze iron phosphide NPs. </LI> <LI> Phase control is critical to optimize catalysis of hydrogen evolution reaction. </LI> <LI> FeP phase with a long reaction time shows the highest HER activity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

알라네이트 계 수소 저장 물질의 수소 방출 특성

정헌도 한국수소및신에너지학회 2017 한국수소 및 신에너지학회논문집 Vol.28 No.4

Alanate-based materials, which were known to have high hydrogen storage capacity, were synthesized by mechanochemically metathesis reaction of metal chloride and sodium alanate without solvent. XRD patterns of synthesized materials showed that metathesis reaction of cations between metal chloride and sodium alanate was progressed favorably without any solvent. Magnesium alanate showed that 3.2 wt.% of hydrogen was evolved by the thermal decomposition. The addition of a small amount of Ti to the magnesium alanate greatly reduced hydrogen evolution temperature. Also, Ti doped magnesium alanate had a good regeneration property. Both the calcium and lithium-magnesium alanate showed the lower starting temperature of the two step hydrogen evolution and fast kinetics for the hydrogen evolution.

Electroactive P-Ani/core-shell/TiO2/TiO2-WO3 employed surface engineering of Ni-P electrodes for alkaline hydrogen evolution reaction

Athira Krishnan,Sheik Muhammadhu Aboobakar Shibli 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.87 No.-

Ni-P coating (NPC) fabricated by electroless deposition has been widely accepted as an effective electrodefor alkaline hydrogen evolution reaction. Among the different strategies reported to improve the catalyticactivity of Ni-P electrode (NPE) further, incorporation of inorganic metal oxide composite is a provenmethod. Herein, we propose a modification of TiO2/TiO2-WO3 core-shell structured composite (a novelentity), by the application of conductive polyaniline (P-Ani), as a continuation of our earlier work on itssynthesis and characterization. The as-prepared polymer-metal oxide hybrid nanocomposite is thenemployed to modify the NPE by electroless deposition method. The improved surface characteristics ofthe modified NPE, after the incorporation of P-Ani/TiO2/TiO2-WO3 composite with reduced chargetransfer resistance and low overpotential for alkaline hydrogen evolution ( 65 mV at10 mA/cm2)corroborates its enhanced catalytic behavior. The increase in the number of catalytically active sites onthe NPE after modification through P-Ani composite is attributed to the enhanced characteristics foralkaline hydrogen evolution. Our strategy proposes a sustainable and low-cost electrode material,competent to the existing industrial electrocatalysts, for long term hydrogen evolution in alkalinemedium.

Application of Spiky Nickel Nanoparticles to Hydrogen Evolution Reaction

Syed Asad Abbas,Ahyeon Ma,Dongho Seo,Yun Ji Lim,Kwang-Deog Jung,Ki Min Nam 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.11

The development of an efficient water splitting catalyst is a requirement for sustainable hydrogen production. Ni catalysts with different shapes were prepared using a solvothermal method for hydrogen evolution reaction (HER). The growth of the Ni particles was manipulated by controlling the reaction temperature and surfactant during the solvothermal reaction. The HER activity of the herein obtained Ni catalysts, namely semi-spherical, dendritic, and spiky nanoparticles were evaluated in alkaline conditions. Spiky Ni nanoparticles exhibited superior HER catalytic activity compared to that of spherical and dendritic Ni nanoparticles. The effect of morphology and electrochemical active sites has been fully investigated.

Electrodeposited Stanene on Ni foam for Hydrogen Cvolution Reaction

Aparna Sajeev(아파르나 사지브),Karthikeyan Krishnamoorthy(케이 카티케이얀),Vimal Kumar Mariappan(비말 구말 마리아판),Parthiban Pazhamalai(파자말라이 파르티반),Sindhuja Manoharan(마노하란 신드후자),Sang-Jae Kim(김상재) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

Hydrogen is a clean green fuel with zero carbon emission and is a potential candidate for the replacement of traditional fossil fuel. The electrochemical hydrogen production through water electrolyzer is one of the promising way to meet the growing renewable energy demand in the global society. In this work, we demonstrated the electrodeposition of binder free stanine on Ni foam for various time interval and analysed their electrocatalytic activity towards hydrogen evolution reaction. Physico-chemical characterization such as X-ray, diffraction, Raman and FESEM analysis confirmed the formation of the stanene on the Ni foam. The electrochemical characterization such as linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy was performed using binder free stanene coated on Ni foam. The obtained results exhibit better catalytic activity towards hydrogen evolution reaction in alkaline.

WS₂ Hollow Sphere Doped by Platinum for High Efficient Hydrogen Evolution Reaction

Minju Chae(채민주),Sujung Suh(서수정),Hanyoung Jung(정한영) 한국신재생에너지학회 2021 한국신재생에너지학회 학술대회논문집 Vol.2021 No.7

Hydrogen is considered an excellent replacement fuel for the efficient and environmentally friendly production of energy. Transition metal dichalcogenides (TMDs) have unique catalytic properties and are earth-abundant, which would allow the production of hydrogen in a facile and low-cost manner. WS<SUB>2</SUB> is a stable and highly active catalyst for the hydrogen evolution reaction (HER). Hollow sphere WS<SUB>2</SUB> nanosheets were synthesized by one-step hydrothermal synthesis, and the prepared WS<SUB>2</SUB> was doped with a platinum chloride solution to enhance HER performance. The diameters of the WS<SUB>2</SUB> hollow spheres were in the range for 400 nm to 2 ㎛, and exhibited an overpotential of 210 mV. The Pt-doped WS<SUB>2</SUB> exhibited an overpotential of 73 mV, which was lower than that of WS<SUB>2</SUB> hollow sphere. Therefore, Pt-doped WS<SUB>2</SUB> is an efficient catalyst for hydrogen evolution reaction. XRD was performed to confirm the crystal structures of the prepared materials. The morphology and composition of the materials were analyzed by SEM and EDS. Raman spectroscopy and TEM were performed to determine the structures and sizes of the materials. The chemical composition was confirmed by XPS.