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Marked CO2 Reduction to Generate C1–C3 Products Using Pt0.9Ru0.1/C-Based Membrane Electrode Assembly at Extremely Low Overpotentials
No full textThe electrochemical CO2 reduction reaction (CO2RR) over Pt electrocatalysts in an aqueous solution system yields mainly H2 and a slight amount of carbon-based products. This limitation can be overcome by using a membrane electrode assembly (MEA) containing a Pt/C electrocatalyst without any overpotential. However, the obtained CO2RR product was only CH4. In this study, we investigated the CO2RR using MEA containing a Pt0.9Ru0.1/C electrocatalyst. Consequently, not only methane as a C1 product but also ethanol as a C2 product and acetone as a C3 product were produced at extremely small overpotentials. This is the first time in the literature that ethanol and acetone were produced from the CO2RR over a Pt–Ru-based electrocatalyst. This fact was confirmed through mass spectrometry, gas chromatography, and isotope labeling experiments. The Faradaic efficiencies of CH4, C2H5OH, and CH3COCH3 were 20.6%, 5.9%, and 5.2%, respectively, and the total Faradaic efficiency was 31.7%. The three products were generated via the Langmuir–Hinshelwood mechanism involving adsorbed CO (COads) and H atoms on the electrocatalyst. The adsorption configuration of COads determines the generation of methane, ethanol, and acetone. The C–C coupling reactions occurred through the formation of COads clusters. Our findings promote the production of valuable C2+ compounds from the CO2RR, which is an important CO2 capture, utilization, and storage technology for realizing carbon neutrality
Semi-analytical solution of axisymmetric indentation of poroelastic multi-layer coating on a substrate
Get PDFWe propose a novel semi-analytical solution of the indentation problem for a poroelastic multi-layer system. This study addresses the time-dependent behavior of materials, such as biological tissues, where mechanical properties vary within the structures. The axisymmetric indentation of a poroelastic multicoating bonded to a poroelastic substrate indented by a rigid, flat-ended cylindrical indenter are investigated. Poroelastic solutions are expressed through two displacement functions, and the transfer matrix method is employed to formulate the effect of a multi-layer composite. In addition, we adopt an analytical method that uses the Laplace–Hankel transform and expresses the normal contact stress at the surface layer as an appropriate series in terms of Chebyshev orthogonal polynomials to reduce the dual integral equations to an infinite system of simultaneous equations in the Laplace transform domain. Subsequently, a numerical inverse Laplace transform is applied to obtain numerical results for the time-dependent consolidation of the rigid cylindrical indenter. Results of consolidation for a single layer bonded to a rigid impervious substrate are consistent with those reported in previous studies. This study examined various combinations of the material properties of a poroelastic multi-layer system. We focus on the effects of the shear modulus, drained and undrained Poisson's ratios, permeability of the surface layer and substrate, and poroelastic layers on the consolidation of the rigid indenter. It is confirmed from the numerical results that consolidation varies with various parameters. These results can be applied to a simplified evaluation of the mechanical properties for multi-layer poroelastic materials by indentation tests
トークンを活用したファンコミュニティによる地域内ネットワークの形成と拡大可能性
Get PDF本研究は、クラウドファンディングの中でトークンを活用したコミュニティが、地域イノベーション創出 に向けてどのように機能するかについて概念的に考察した。クラウドファンディングによる地域外ネット ワークとしてのファンコミュニティには、継続的なプロジェクトの立ち上げとともに、単発的ではあるが再 度の資金調達を可能にするという利点と、新たに資金を提供するファンの獲得という経済的効果に直結する ファンコミュニティの拡大が期待できる。本研究では、ファンコミュニティにトークンを活用し、地域課題 解決プロジェクトを実施しているケースサイトの活動を基に考察を行い、トークンは、CF による地域イノ ベーション創出において地域経済活性化と地域交流活性化を分離する効果を持ち、主に地域交流活性化を目 的とした地域内ネットワークの形成・拡大に繋がることを示した。この形成と拡大は、地域交流活性化活動 を通して経済的成果への循環を生み出すことが期待され、地域課題解決以外にも地域経済活性化への貢献が 期待される
