Article
Materials Science, Multidisciplinary
Chun Ouyang, Damao Xun, Gang Jian
Summary: N-doping and sulfonation were used to prepare PtNi nanoparticles supported on reduced graphene oxide (rGO) through hydrothermal synthesis and thermal decomposition. The specific surface area and catalytic stability of the PtNi/S-(N)rGO catalyst were improved by the anchoring effect of sulfonated groups and evenly distribution of nanoparticles, respectively. The synergistic effect of N-doping and sulfonation led to an increase in catalytic efficiency through an increase in the number of electron transfer.
Article
Chemistry, Physical
Shiqing Huang, Zelong Qiao, Panpan Sun, Kangwei Qiao, Kun Pei, Liu Yang, Haoxiang Xu, Shitao Wang, Yan Huang, Yushan Yan, Dapeng Cao
Summary: A new Fe-Mn-N-C dual-atom catalyst has been synthesized in this study, which improves the activity of oxygen reduction reaction by tailoring its electronic structure, and exhibits excellent performance in proton/anion-exchange membrane fuel cells.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Engineering, Environmental
Srinu Akula, Marek Mooste, Jekaterina Kozlova, Maike Kaarik, Alexey Treshchalov, Arvo Kikas, Vambola Kisand, Jaan Aruvali, Paarn Paiste, Aile Tamm, Jaan Leis, Kaido Tammeveski
Summary: Delving into highly active and cost-efficient electrocatalysts for oxygen reduction reaction (ORR) is crucial for large-scale application of polymer electrolyte fuel cells. Anion exchange membrane fuel cells (AEMFCs) are promising clean energy devices with mild reaction conditions and the possibility of employing Pt-free catalysts for ORR. This study focuses on the development of non-Pt catalysts for AEMFC by preparing metal-nitrogen-carbon (M-N-C) electrocatalysts through a robust synthesis method using transition metal impregnated melamine-phloroglucinol-formaldehyde (MPF) polymeric networks. The catalysts with optimized metal content and pyrolysis temperature showed enhanced ORR performance due to their prominent textural properties and efficient active centers. Iron-doped (MPF/Fe) and cobalt-doped (MPF/Co) catalysts performed the best with half-wave potential (E1/2) values of 0.81 and 0.80 V vs RHE, attributed to the highly active M-Nx sites and hierarchical porous structure. The outstanding electrochemical stability and high-power density in AEMFC (up to 347 mW cm-2) demonstrate the potential of these M-N-C catalysts for fuel cell applications.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Sumanta Kumar Das, Aiswarya Kesh, Srinu Akula, Subhendu K. Panda, G. V. M. Kiruthika, Akhila Kumar Sahu
Summary: In this study, nonprecious metal electrocatalysts were developed by borylation of graphitic carbon nanofiber (GNF) and codoping of Co, Ni. The resulting catalyst showed enhanced oxygen reduction reaction (ORR) activity and was successfully applied in anion exchange membrane fuel cells (AEMFCs). The combination of boron doping and Ni, Co doping increased positive charge clouds surrounding metal centers, facilitating O-2 adsorption and catalytic activity. The catalyst exhibited excellent ORR activity and CH3OH tolerance in alkaline medium, making it a promising cathode catalyst for AEMFC applications. The study demonstrated the importance of nonprecious metal catalysts in the development of low-cost and highly efficient electrocatalysts for AEMFCs.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Polymer Science
Yu-Wei Cheng, Tar-Hwa Hsieh, Yu-Chang Huang, Po-Hao Tseng, Yen-Zen Wang, Ko-Shan Ho, Yue-Jie Huang
Summary: In this study, a polyazomethine gel crosslinked with Co ions was prepared from the polycondensation between p-phenylene diamine and p-terephthalaldehyde. The gel was calcined to form a Co, N-co-doped carbonaceous matrix, which acted as a cathode catalyst for an anion exchange membrane fuel cell. The Co-N-C catalyst showed a single-atom structure with active Co centers and exhibited high catalytic activity and power density.
Article
Chemistry, Physical
Jaana Lilloja, Elo Kibena-Poldsepp, Ave Sarapuu, John C. Douglin, Maike Kaarik, Jekaterina Kozlova, Paarn Paiste, Arvo Kikas, Jaan Aruvali, Jaan Leis, Vaino Sammelselg, Dario R. Dekel, Kaido Tammeveski
Summary: The transition-metal- and nitrogen-codoped carbide-derived carbon/carbon nanotube composites have been prepared and characterized as cathode catalysts in anion-exchange membrane fuel cells. These catalysts exhibit excellent electrocatalytic performance, stability, and have a good combination of micro- and mesoporous structures. The CoFe-N-CDC/CNT material shows a current density close to 500 mA cm(-2) at 0.75 V and a peak power density exceeding 1 W cm(-2) in H-2/O-2 AEMFCs.
Article
Chemistry, Multidisciplinary
Pengyu Han, Xinyi Yang, Liqing Wu, Hongnan Jia, Jingchao Chen, Wenwen Shi, Gongzhen Cheng, Wei Luo
Summary: In this study, a new catalyst, boron interstitially inserted ruthenium, is synthesized and used as an anode catalyst for anion exchange membrane fuel cells. The experimental results show that this catalyst exhibits higher activity for the hydrogen oxidation reaction in alkaline electrolyte compared to acidic electrolyte. Further experiments and theoretical calculations reveal that the enhanced performance is attributed to the changes in the electronic structure of ruthenium after the introduction of interstitial boron.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jong Gyeong Kim, Sunghoon Han, Chanho Pak
Summary: The study investigated the effects of phosphoric acid (PA) activation and phosphorus doping on Fe-N-C catalysts, finding that the amount of PA added influenced pore structure and catalytic activity. The electronic states of Fe, N, and P were analyzed, showing stability improvements in Fe-N-C catalysts with the introduction of PA.
Article
Chemistry, Physical
Iris Palm, Elo Kibena-Poldsepp, Marek Mooste, Jekaterina Kozlova, Maike Kaarik, Arvo Kikas, Alexey Treshchalov, Jaan Leis, Vambola Kisand, Aile Tamm, Steven Holdcroft, Plamen Atanassov, Kaido Tammeveski
Summary: The preparation of dual heteroatom-doped SiCDC/CNT catalysts for ORR exhibited high catalytic activity and impressive performance in AEMFC tests, attributed to their high specific surface area, hierarchical porosity, high defect density, and successful doping of N and P elements.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Liu Yang, Huibing Liu, Zelong Qiao, Panpan Sun, Danyang Li, Run Jiang, Shengwen Liu, Ziqiang Niu, Yongguang Zhang, Ting Lin, Qinghua Zhang, Lin Gu, Shitao Wang, Dapeng Cao, Zhongwei Chen
Summary: In this study, a metal-free carbon catalyst NDPC-1000 with a graphitic N-regulating defect structure was designed for anion-exchange membrane fuel cells (AEMFCs) through theoretical calculations and experiments. The graphitic N was found to tailor the charge density of defects to enhance the adsorption energy-activity relation, and the high durability was attributed to the dissociation energy of the C-N covalent bond. The synthesized NDPC-1000 demonstrated excellent ORR activity and durability in alkaline media, achieving a peak power density of 913 mW cm(-2) and a voltage decay of approximately 25% after 100 hours of continuous operation.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Rong Ren, Xiaojiang Wang, Hengquan Chen, Hamish Andrew Miller, Ihtasham Salam, John Robert Varcoe, Liang Wu, Youhu Chen, Hong-Gang Liao, Ershuai Liu, Francesco Bartoli, Francesco Vizza, Qingying Jia, Qinggang He
Summary: Researchers developed a structural engineering strategy to immobilize a molecular catalyst onto an ionomer, creating a composite material with a homogeneous catalysis environment inside ion-flow channels. This led to significantly improved mass transfer and turnover frequency due to 100% utilization of catalyst molecules, resulting in advantages of low overpotential and high fuel-cell power density in the homogeneous catalysis system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jingyu Feng, Rongsheng Cai, Emanuele Magliocca, Hui Luo, Luke Higgins, Giulio L. Fumagalli Romario, Xiaoqiang Liang, Angus Pedersen, Zhen Xu, Zhenyu Guo, Arun Periasamy, Dan Brett, Thomas S. Miller, Sarah J. Haigh, Bhoopesh Mishra, Maria-Magdalena Titirici
Summary: Atomically dispersed transition metal-nitrogen-carbon catalysts are emerging as low-cost electrocatalysts for the oxygen reduction reaction in fuel cells. A synthesis strategy for these catalysts is still required, as well as a greater understanding of their mechanisms. Iron, nitrogen co-doped carbon spheres (Fe@NCS) have been prepared and FeN4 is identified as the main form of iron existing in the obtained Fe@NCS. Starting from Fe2+ and Fe3+ precursors, catalysts show chemical and structural differences. Fe2+@NCS-A displays better catalytic activity for the oxygen reduction reaction and shows potential for developing high-performance, low-cost fuel cell catalysts.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Physical
Srinu Akula, Marek Mooste, Barr Zulevi, Sam McKinney, Arvo Kikas, Helle-Mai Piirsoo, Mihkel Rahn, Aile Tamm, Vambola Kisand, Alexey Serov, Erin B. Creel, David A. Cullen, Kenneth C. Neyerlin, Hao Wang, Madeleine Odgaard, Tatyana Reshetenko, Kaido Tammeveski
Summary: The new PGM-free PEMFC cathode catalyst materials synthesized using the VariPore (TM) method by Pajarito Powder, LLC show high activity and stability, with mesoporous structure facilitating an effective reaction path.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Mohsin Muhyuddin, Ariel Friedman, Federico Poli, Elisabetta Petri, Hilah Honig, Francesco Basile, Andrea Fasolini, Roberto Lorenzi, Enrico Berretti, Marco Bellini, Alessandro Lavacchi, Lior Elbaz, Carlo Santoro, Francesca Soavi
Summary: Metal-nitrogen-carbons (M-N-Cs) are reliable substitutes for platinum-group-metals (PGMs) for oxygen reduction reaction (ORR), and can be economically produced by utilizing waste biomass as a low-cost carbon source. In this study, electrocatalysts derived from lignin-derived activated char were fabricated and characterized. The results showed that the metal phthalocyanine-functionalized activated char exhibited defect-rich architecture and various nitrogen-containing active moieties, leading to appreciable ORR activity in both acidic and alkaline conditions. Moreover, the integrated L_FeMn cathode electrocatalyst demonstrated promising performance in both PEMFC and AEMFC, with a peak power density of 261 mW cm-2 at -577 mA cm-2.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Jonas Mart Linge, Heiki Erikson, Marek Mooste, Helle-Mai Piirsoo, Tiit Kaljuvee, Arvo Kikas, Jaan Aruvali, Vambola Kisand, Aile Tamm, Arunachala M. Kannan, Kaido Tammeveski
Summary: Two different wet chemical methods were used to deposit silver nanocatalyst (40 wt%) on commercial mesoporous carbon support material (Ag/C) to enhance the electrochemically active surface area. The catalyst materials were characterized using various analytical techniques and evaluated for oxygen reduction reaction (ORR) in alkaline media. The Ag/C catalyst exhibited higher mass activity for ORR compared to Vulcan carbon, showing potential for application in anion exchange membrane fuel cells.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
