Article
Chemistry, Physical
Anchu Ashok, Anand Kumar, Afdhal Yuda, Abdullah Al Ashraf
Summary: This study reports the preparation of a highly active catalyst, N,S-Co@CNT, which is derived from hierarchical Co9S8 nanowires trapped in Ndoped carbon nanotubes. Compared to traditional Co@CNT, N,S-Co@CNT exhibits higher current density and lower onset potential, attributed to its unique hierarchical structure and surface properties.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Yangyang Ren, Zehao Zang, Chenhao Lv, Beibei Li, Lanlan Li, Xiaojing Yang, Zunming Lu, Xiaofei Yu, Xinghua Zhang
Summary: Highly durable and active PtCuCo nanoframes were prepared as enhanced bifunctional electrocatalysts for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in acidic environment. The PtCuCo nanoframes exhibited remarkable activity and durability due to their ternary compositions and structure-fortifying frame structures. The specific/mass activity of PtCuCo nanoframes for ORR in perchloric acid solution was 12.8/7.5 times as large as that of commercial Pt/C, while for MOR in sulfuric acid solution, the mass/specific activity was 5.4/9.4 times as large as that of Pt/C. This work may provide a promising nanoframe material for developing dual catalysts for fuel cells.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Guanzhi Wang, Jinfa Chang, Supriya Koul, Akihiro Kushima, Yang Yang
Summary: The novel dynamic CO2-bubble template approach was able to electrochemically fine-tune the exposed Pt active sites in PtFeNi porous films, leading to improved activity for oxygen reduction and evolution reactions. This method achieved high power density and durability in Zn-air batteries, demonstrating the efficiency of microstructure tuning for enhancing PGM catalyst activity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Quentin Lenne, Alice Mattiuzzi, Ivan Jabin, Ludovic Troian-Gautier, Jonathan Hamon, Yann R. Leroux, Corinne Lagrost
Summary: A single material electrocatalyst with high activity and durability for both ORR and MOR is a conceptual challenge in designing versatile DMFCs. By using a supramolecular concept, surface-grafted molecular ligands can regulate the reactivity of Pt catalyst, leading to Pt CF3 ${{_{{\rm CF}{_{3}}}}}$ NPs/C with remarkable methanol tolerance, outstanding durability, and chemical stability. This research highlights a promising strategy for tuning interfacial properties, providing a potential solution for the design of DMFC cathodic and anodic compartments.
Article
Chemistry, Physical
Simona Somacescu, Petre Osiceanu, Jose Maria Calderon Moreno, Daniela C. Culita, Florentina Neatu, Mihaela M. Trandafir, Stefan Neatu, Andrei Kuncser, Gaobr P. Szijjarto, Emilia Talas, Andras Tompos, Irina Borbath, Mihaela Florea
Summary: A direct synthesis route was developed to prepare mesoporous NiWO4 and NiWO4-graphene nanoplatelets (GNP) composite with crystalline framework. The introduced GNP enhanced the growth of NiWO4 nanocrystallites and induced changes in surface chemistry. The Pt/NiWO4-GNP catalyst showed significantly higher activity in oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) compared to other catalysts. This composite material is considered as a viable electrocatalyst for PEMFCs using a broader type of fuels.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Caijin Shi, Xieraili Maimaitiyiming
Summary: Efforts have been made to develop efficient and durable bifunctional catalysts for oxygen reduction reaction and methanol oxidation reaction, leading to the fabrication of a series of new three-dimensional nitrogen, phosphorus and sulfur doped porous graphene (NPS G) as efficient electrocatalysts. The optimized NPS G(2) catalyst exhibited superior catalytic activities with long-term stability and excellent methanol poisoning tolerance, showing promising potential in direct methanol fuel cells and methanol electrooxidation reactions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Multidisciplinary Sciences
Yanbin Qi, Yue Zhang, Li Yang, Yuhan Zhao, Yihua Zhu, Hongliang Jiang, Chunzhong Li
Summary: Understanding the effect of methanol concentration on Ni3B/Ni heterostructures during formate production, the authors used operando spectroscopies and found that high concentrations of methanol inhibit the phase transition of the electrocatalyst and form electrophilic oxygen species as catalytically active species.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Amir A. Rezaie, Eunsoo Lee, Diana Luong, Johan A. Yapo, Boniface P. T. Fokwa
Summary: Research has shown that van der Waals metal chalcogenide Fe3GeTe2 possesses high activity in both basal planes and edge sites for the hydrogen evolution reaction. Treatment methods can significantly improve the HER activity, opening up new avenues for designing high-performing electrocatalysts using related iron-based van der Waals materials, composites, and surface functionalization.
ACS MATERIALS LETTERS
(2021)
Article
Chemistry, Physical
Gerard Malefane Leteba, David Richard Graham Mitchell, Lebohang Macheli, Pieter B. J. Levecque, Bryan P. Doyle, Eric van Steen, Candace I. Lang
Summary: Molybdenum-modified platinum nanoparticles exhibit superior electrocatalytic properties compared to pure platinum nanoparticles, showing excellent catalytic performance and enhanced stability. These performances are attributed to the concave structures, variations in vertex chemistry, and platinum enrichment of the platinum-solute molybdenum nanoalloys.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Jincheng Zhang, Qilun Wang, Chunyu Qiu, Liyong Gan, Jie Ding, Fuhua Li, Tian Wang, Yuhang Liu, Yucheng Wang, Huabing Tao, Sung-Fu Hung, Hongbin Yang, Bin Liu
Summary: In this study, we developed a low-cost and highly efficient oxygen reduction reaction (ORR) catalyst Fe1/NSG by anchoring single Fe atoms on N,S-codoped graphene. The Fe catalyst center with S atoms in the second coordination sphere regulates the electronic structure and stabilizes the *OOH intermediate in the ORR. Fe1/NSG exhibited high ORR activity with a half-wave potential of 0.90 V vs. RHE and excellent methanol tolerance. The DMFC with Fe1/NSG cathode achieved a peak power density of 198 mW cm-2, outperforming DMFCs assembled with non-precious-metal-based cathode catalysts.
CELL REPORTS PHYSICAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Xing Wu, Qichen Wang, Shize Yang, Jinyang Zhang, Yi Cheng, Haolin Tang, Lu Ma, Xiaobo Min, Chongjian Tang, San Ping Jiang, Feixiang Wu, Yongpeng Lei, Simone Ciampic, Shuangyin Wang, Liming Dai
Summary: Carbon supported single atom catalysts (SACs) have shown great potential as effective electrocatalysts in energy storage and conversion devices. This research demonstrates that by controlling the layers of single atom active sites, the catalysts exhibit enhanced activity in the oxygen reduction reaction (ORR), leading to higher turnover frequency (TOF) and reducing the reaction overpotential. The newly-developed catalysts with sublayer-enhanced active sites also show significantly improved performance in alkaline and acidic conditions, making them promising for applications in Zn-air batteries and fuel cells.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Fei Gao, Yangping Zhang, Huaming You, Zhuolin Li, Bin Zou, Yukou Du
Summary: In this study, a one-pot, surfactant-free approach was developed to obtain a PdPtAu@Pd core@shell catalyst for the photocatalytic methanol oxidation reaction. The 0D@2D PdPtAu@Pd catalyst exhibited superior catalytic performance compared to Pt/C and Pd/C catalysts, with a mass activity 2.3- and 6.7-times higher, respectively.
CHEMICAL COMMUNICATIONS
(2021)
Review
Chemistry, Multidisciplinary
Tianlei Wang, Arunabhiram Chutia, Dan J. L. Brett, Paul R. Shearing, Guanjie He, Guoliang Chai, Ivan P. Parkin
Summary: Palladium-based alloy materials are being considered as potential substitutes for platinum-based catalysts in fuel cells for the reduction of oxygen. Through a scientometric analysis, research fronts and hotspots have been identified, with volcano plots showing general principles for catalyst modifications to enhance the oxygen reduction reaction. Various influencing factors, such as alloying, structure, and particle size, are discussed for their potential in improving the ORR activity.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Green & Sustainable Science & Technology
Keyru Serbara Bejigo, Subramanian Natarajan, Kousik Bhunia, Vijayakumar Elumalai, Sang-Jae Kim
Summary: Environmentally friendly technology for recycling spent lithium-ion battery (LIB) electrodes was developed to explore the efficiency of regenerated electrocatalysts for electrochemical oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). The process involved lixiviation of LixCoO2 electrodes using tartaric acid and H2O2, conversion of graphite into graphene oxide (GO), and regeneration of cobalt oxide-supported reduced graphene oxide (Co3O4/rGO). The regenerated composite material exhibited good activity for ORR and MOR, indicating the potential utilization of end-of-life LIBs as high-performance electrocatalysts in energy conversion devices.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Chemistry, Multidisciplinary
Tianyu Xia, Kai Zhao, Youqi Zhu, Xiaoyan Bai, Han Gao, Ziyu Wang, Yue Gong, Menglin Feng, Shunfang Li, Qiang Zheng, Shouguo Wang, Rongming Wang, Haizhong Guo
Summary: Mixed-dimensional Pt-Ni alloy polyhedral nanochains were fabricated to address the unbalanced relationship between activity and stability in Pt nanocatalysts. These nanochains exhibited significantly enhanced mass activity for methanol oxidation reaction and improved stability against CO poisoning. Additionally, they achieved a higher half-wave potential for oxygen reduction reaction.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Matija Gatalo, Alejandro Martinez Bonastre, Leonard Jean Moriau, Harriet Burdett, Francisco Ruiz-Zepeda, Edwin Hughes, Adam Hodgkinson, Martin Sala, Luka Pavko, Marjan Bele, Nejc Hodnik, Jonathan Sharman, Miran Gaberscek
Summary: This study systematically addresses the challenges of synthesis, activation, and stability of Pt-alloy electrocatalysts. It highlights the crucial importance of the chemical activation step and provides a simple method to distinguish the degree of activation. Additionally, the study presents clear evidence on the direct impact of the lower voltage limit on the stability of electrocatalysts.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Electrochemistry
Gorazd Koderman Podborsek, Ana Rebeka Kamsek, Anja Loncar, Marjan Bele, Luka Suhadolnik, Primoz Jovanovic, Nejc Hodnik
Summary: This study utilized a unique method to investigate the structural transformations of Ir nanoparticles on an Ir/TiON-based TEM grid, revealing surface roughening as the predominant degradation mechanism and directly confirming the suppressed oxidation tendency of supported Ir.
ELECTROCHIMICA ACTA
(2022)
Article
Electrochemistry
Stefan Popovic, Mohammed Azeezulla Nazrulla, Primoz Sket, Khaja Mohaideen Kamal, Blaz Likozar, Luka Suhadolnik, Luka Pavko, Angelja Kjara Surca, Marjan Bele, Nejc Hodnik
Summary: This study establishes an optimized method for the synthesis of chloride-free cuprous oxide nanocubes (Cu2O NCs) and investigates the influence of returning to the open-circuit potential (OCP) before electrolysis on the CO2RR activity/selectivity.
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Philipp A. Heizmann, Hien Nguyen, Miriam von Holst, Andreas Fischbach, Mitja Kostelec, Francisco Javier Gonzalez Lopez, Marjan Bele, Luka Pavko, Tina Dukic, Martin Sala, Francisco Ruiz-Zepeda, Carolin Klose, Matija Gatalo, Nejc Hodnik, Severin Vierrath, Matthias Breitwieser
Summary: The design of stable and finely dispersed platinum or platinum alloy nanoparticles on the carbon support is crucial for controlling the performance of PEM fuel cells. In this study, a PtCo/C catalyst with intermetallic structures is synthesized and shows significantly narrowed particle size distribution compared to commercial benchmark catalysts. The improved dispersion of PtCo particles leads to an increase in electrochemically active surface area and a more efficient usage of precious metal, resulting in enhanced performance of PEM fuel cells.
Article
Chemistry, Physical
Luka Suhadolnik, Marjan Bele, Miha Cekada, Primoz Jovanovic, Nik Maselj, Anja Loncar, Goran Drazic, Martin Sala, Nejc Hodnik, Janez Kovac, Tiziano Montini, Michele Melchionna, Paolo Fornasiero
Summary: A versatile approach for producing cluster- and single atom-based thin-film electrode composites is described in this article. The TiOxNy-Ir catalyst developed in this study was prepared from sputtered Ti-Ir alloy with 0.8 +/- 0.2 at % Ir in alpha-Ti solid solution. The prepared catalyst exhibited high oxygen evolution reaction activity and has potential applications in electrocatalysis. The article provides a detailed description of the new method and a high-performance thin film catalyst, along with suggestions for future development in this field.
CHEMISTRY OF MATERIALS
(2023)
Article
Electrochemistry
Anja Loncar, Primoz Jovanovic, Nejc Hodnik, Miran Gaberscek
Summary: Recently, a method for determining the actual electrochemically active surface area (ECSA) based on impedance response and adsorption capacity has been proposed. In this paper, the method is applied to characterize Ir-based nanostructured electrocatalysts. Experimental results show deviations from the predicted scaling, which are further analyzed by considering charge transfer resistance, adsorption resistance, and double layer capacitance. Impedance simulations using a full physical model are used to confirm the hypotheses and propose possible reasons for the anomalies.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Maximilian Grandi, Matija Gatalo, Ana Rebeka Kamsek, Gregor Kapun, Kurt Mayer, Francisco Ruiz-Zepeda, Martin Sala, Bernhard Marius, Marjan Bele, Nejc Hodnik, Merit Bodner, Miran Gaberscek, Viktor Hacker
Summary: Platinum-copper catalysts have shown high activity for the oxygen reduction reaction (ORR), but transferring this activity to membrane electrode assemblies (MEAs) has been challenging due to stability issues. The catalysts experience fast performance decay when exposed to repeated voltage load steps with H-2/air supplied. This decay is accelerated by high humidity and low voltage polarization. The use of electrochemical impedance spectroscopy and distribution of relaxation time analysis (EIS-DRT) has helped identify the affected electrochemical processes and suggested improvements for the PtCu/KB catalyst system.
Article
Energy & Fuels
Nik Maselj, Vasko Jovanovski, Francisco Ruiz-Zepeda, Matjaz Finsgar, Tamara Klemencic, Jan Trputec, Ana Rebeka Kamsek, Marjan Bele, Nejc Hodnik, Primoz Jovanovic
Summary: In this study, a comparative analysis of two catalysts for electrocatalytic hydrogenation of furfural under acidic conditions was conducted. The catalysts analyzed were a copper polycrystalline disc and copper nanoparticles dispersed on carbon support. A task-specific methodology based on electrochemistry-mass spectrometry coupling was employed to gain insight into the trends of the hydrogenation reaction. The results showed that the nanoparticulate catalyst exhibited higher activity towards hydrogen evolution and 2-MF production, while the polycrystalline catalyst showed higher selectivity towards furfuryl alcohol. The observed differences in activity were attributed to alterations in surface domains, as supported by surface-sensitive lead underpotential deposition characterization.
Article
Nanoscience & Nanotechnology
Marjan Bele, Gorazd Koderman Podborsek, Anja Loncar, Primoz Jovanovic, Armin Hrnjic, Ziva Marinko, Janez Kovac, Angelja Kjara Surca, Ana Rebeka Kamscek, Goran Drazic, Nejc Hodnik, Luka Suhadolnik
Summary: Introducing the Nano Lab, a novel experimental platform aimed at accelerating the discovery and understanding of promising electrocatalysts. It enables state-of-the-art physicochemical characterization and atomic-scale tracking of individual synthesis steps as well as subsequent electrochemical treatments targeting nanostructured composites. The platform's compatibility with ex situ characterization and other analytical methods allows for a comprehensive understanding of structural changes and their effects.
ACS APPLIED NANO MATERIALS
(2023)
Article
Electrochemistry
Sigrid Wolf, Michaela Roschger, Bostjan Genorio, Nejc Hodnik, Matija Gatalo, Francisco Ruiz-Zepeda, Viktor Hacker
Summary: In this study, researchers synthesized a PdNiBi nanocatalyst on reduced graphene oxide (rGO) using a facile method, which showed higher activity and stability in alkaline direct ethanol fuel cells (ADEFCs). The characterization and electrochemical tests indicated that PdNiBi/rGO had more active sites and exhibited better catalytic performance compared to commercial Pd/C.
JOURNAL OF ELECTROCHEMICAL SCIENCE AND ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Hsin-Chia Ho, Milutin Smiljanic, Zoran Jovanovic, Miha Cekada, Janez Kovac, Gertjan Koster, Jiri Hlinka, Nejc Hodnik, Matjaz Spreitzer
Summary: This study developed a robust photocathode using low-cost and high-performing materials, such as p-Si, for efficient and durable production of clean fuel hydrogen. The utilization of pulsed laser deposition (PLD) technique and a buffer layer of reduced graphene oxide (rGO) allowed for the preparation of a high-quality SrTiO3 (STO) layer that passivates the p-Si substrate. The study demonstrated that the epitaxial STO layer on rGO-buffered Si provided the highest onset potential and improved charge separation and transfer compared to counterparts with thicker or nonepitaxial STO layers. The importance of having a well-defined passivation layer and the stability of the epitaxial STO layer in corrosion resistance was also highlighted.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Luka Pavko, Matija Gatalo, Tina Dukic, Francisco Ruiz-Zepeda, Angelja Kjara Surca, Martin Salad, Nik Maselj, Primoz Jovanovic, Marjan Bele, Matjaz Finsgar, Bostjan Genorio, Nejc Hodnik, Miran Gaberscek
Summary: This study evaluates the durability of carbon support materials for Pt alloy nanoparticles and finds that the total amount of oxygen functionalities, the type of oxygen functionalities, and sp2 carbon content play a crucial role in carbon support durability. The findings are confirmed with direct online measurements of carbon corrosion via an advanced in-situ technique.
Article
Electrochemistry
Ozbej Vodeb, Anja Loncar, Marjan Bele, Armin Hrnjic, Primoz Jovanovic, Miran Gaberscek, Nejc Hodnik
Summary: Water splitting in acidic media is an effective method for producing hydrogen fuel, but the oxygen evolution reaction (OER) remains a bottleneck. This study investigates the OER mechanism of three different Ir-based catalysts and the activation process. The results show that all catalysts share the same OER mechanism but require different amounts of activation cycles. This study provides insights into the intrinsic properties of different Ir nanocatalysts and presents a general approach for studying the reaction mechanisms and intrinsic properties of electrocatalysts.
ELECTROCHIMICA ACTA
(2023)
Article
Nanoscience & Nanotechnology
A. R. Kamsek, A. Meden, I. Arcon, P. Jovanovic, M. Sala, F. Ruiz-Zepeda, G. Drazic, M. Gaberscek, M. Bele, N. Hodnik
Summary: In order to reduce the cost of electrocatalysts for oxygen reduction reactions in proton exchange membrane fuel cells, supported metal alloy nanoparticles are commonly used. This study focused on investigating the presence of periodic anti-phase boundaries in carbon-supported PtCu3 nanoparticles. Various characterization tools were used to observe the formation and disappearance of these boundaries. The electrocatalytic activity for the oxygen reduction reaction was determined and correlated with the degree of alloy ordering rather than the presence of anti-phase boundaries.
MATERIALS TODAY NANO
(2023)
Article
Chemistry, Multidisciplinary
L. Moriau, K. Stojanovski, P. Jovanovic, D. Escalera-Lopez, S. Cherevko, N. Hodnik
Summary: The utilization of iridium is expected to increase due to the rising implementation of water electrolyzer devices in the energy transition. However, its limited natural resources make recycling important. The most corrosion resistant platinum group metal, iridium, makes its recovery from waste difficult and energy-demanding. This study examines the impact of organics and chloride ions on the electrochemical dissolution of iridium for green recycling purposes.
