2024/02/14

Efficient preparation of carbon materials composed of warped graphene layers via in-situ nano-templating and estimation of oxygen reduction reaction activity https://doi.org/10.1016/j.carbon.2024.118910 The warped graphene layer (WGL) has garnered attention as a potential alternative to Pt for oxygen reduction reaction (ORR) catalysts and as a platform for enhancing the activity of Pt or molecular catalysts through interactions. We propose an in-situ nano-templating method for the preparation and mass production of WGLs and demonstrate its efficiency. The in-situ nano-templating method facilit...続きを読む »

2023/12/29

Construction of Warped Graphitic Layers from Fullerene Soot and Study of Their Catalytic Oxygen Reduction Activity https://pubs.acs.org/toc/jpccck/127/51 Heat treatment of WGL-O, identified by its curvature in carbon layers, results in the formation of warped graphitic layers (WGLs). These layers show significant catalytic activity in the reduction of oxygen, indicating potential applications in catalysis....続きを読む »

2023/12/19

Construction of Warped Graphitic Layers from Fullerene Soot and Study of Their Catalytic Oxygen Reduction Activity https://doi.org/10.1021/acs.jpcc.3c06030 Platinum is widely used in cathode catalysts for fuel cells; however, it is expensive, with limited reserves. Hence, the development of non-Pt catalysts has been extensively studied. Carbon alloy catalysts are considered the most potent alternatives to Pt-based catalysts. However, the catalytic activity of carbon, which is the primary constituent of carbon alloy catalysts, in oxygen reduction reactions (ORRs) has been insufficiently investi...続きを読む »

2023/11/23

Development of an electrochemical system to measure high-temperature oxygen reduction for the electrochemical evaluation of Pt/C and non-precious metal catalysts https://doi.org/10.1016/j.ijhydene.2023.11.131 In polymer electrolyte fuel cells, the oxygen reduction reaction (ORR) rate increases at high temperatures. Therefore, ORR catalysts must be designed for use at high temperatures and require evaluation. To address the problem of decreased dissolved oxygen concentrations in conventional channel flow double electrode (CFDE) systems, this study develops a CFDE system capable of electrochemic...続きを読む »

2023/06/01

Molecular-level understanding of carbon materials by temperature-programmed desorption https://doi.org/10.7209/carbon.020203 A wide variety of surface functional groups, such as oxygen-containing ones and hydrogen, exist at the graphene edge sites of carbon materials. Because the presence of these functional groups greatly affects the chemical properties of carbon-based materials produced from them, knowledge of the edge site state is essential to understand carbon chemistry. This review describes the analyses of edge sites and carbon-material structures by temperature-programmed desorption (T...続きを読む »

2023/02/23

Chemical modification of carbon edge sites using trimethylaluminum to enhance the oxidation resistance of carbon materials https://doi.org/10.1016/j.carbon.2023.02.059 As the oxidation of carbon materials proceeds from chemically reactive carbon edge sites, increasing the chemical stability of carbon edge sites is expected to increase the oxidation resistance. In this study, we developed a method for enhancing the chemical stability of carbon materials by modifying the carbon edge sites with chemically stable metal oxides. We focused on aluminol as a potentially stable metal oxide and introduc...続きを読む »

2022/12/01

What can we learn by analyzing the edge sites of carbon materials? https://doi.org/10.7209/carbon.010406 Because the chemical features of carbon materials strongly depend on the number and the type of edge sites, it is crucial to analyze them in order to understand their performance at the molecular level. For the analysis of carbon edge sites, temperature programmed desorption (TPD) has often been used, because it is simple but effective. Recently, a new type of TPD apparatus was developed by our group which can reach a TPD temperature as high as 1800 °C and has a very high sensitivity for th...続きを読む »

2022/06/13

Estimation of the spatial distribution of carbon edge sites in a carbon structure using H2 desorption kinetics in temperature programmed desorption https://doi.org/10.1016/j.carbon.2022.06.006 This study aims to elucidate the role of hydrogen desorption profiles obtained through temperature programmed desorption (TPD) analysis of carbon materials for revealing their carbon edge sites. Accordingly, the H2 desorption profiles of several carbon materials, such as activated carbon, carbon black, reduced graphene oxide (rGO), phenol resin carbon, graphite, high-temperature treated carbon, and carbo...続きを読む »

2022/05/03

Modulation of the electronic state of carbon thin films by inorganic substrates https://www.sciencedirect.com/science/article/pii/S0008622322003578?via%3Dihub The control of the electronic states of carbon-based materials is of great importance for the widespread use of carbon materials as electronic devices and catalysts. This article reports a novel method of controlling the electronic states of carbon-based materials by establishing covalent bonds between inorganic support materials and carbon thin films. Carbon thin films of 1 nm thickness were grown on inorganic substrates (Al2O3, AlN, an...続きを読む »

2022/01/07

Preparation of Chemically Structure-Controlled BN-Doped Carbons for the Molecular Understanding of Their Surface Active Sites for Oxygen Reduction Reaction https://pubs.acs.org/doi/abs/10.1021/acscatal.1c04806 BN-doped carbons have been reported to exhibit higher oxygen reduction reaction (ORR) activities than single-atom-doped carbons. However, the structures of these BN-doped carbons as well as the mechanism underlying their catalytically active sites had not been elucidated. In the BN-doped carbons reported so far, B and N exist in a disordered manner within the carbon structure. Therefore,...続きを読む »