Life cycle assessment shows that retrofitting coal-fired power plants with fuel cells will substantially reduce greenhouse gas emissions

Addressing emissions released from coal-fired power plants (CFPPs) is vital to mitigate climate change. China aims to replace 240 TWh CFPPs with fuel cell (FC) technologies by 2050 to achieve carbon-neutrality goals. However, FCs are not emission-free throughout their technology life cycle, and FC effectiveness will vary depending on the CFPP configuration. Despite these uncertainties, a comprehensive evaluation of on-site CFPP-to-FC mitigation potential throughout the entire life cycle remains underexplored. Here, we use a prospective life cycle assessment to evaluate the inclusive mitigation potential of retrofitting 240 TWh CFPPs via four FCs that use wind power/natural gas as feedstocks. We find CO2, PM2.5, and SO2 emissions decrease by 72.0%–97.0%, 55.5%–92.6%, and 23.1%–86.1%, respectively, by 2050. Wind-electrolysis hydrogen FCs enable the largest life cycle CO2 reduction, but mining metals for wind turbines reduces PM2.5 and SO2 savings. Prioritizing FC deployment in northern China could double the mitigation potential. Our study provides insights for designing carbon-neutrality CFPP-to-FC roadmaps in China

First-principles study of initial oxygen reduction reaction on stoichiometric and reduced CeO2 (111) surfaces as cathode catalyst for lithium-oxygen batteries

CeO2 has been explored as an electro-catalyst in the cathode of lithium-oxygen batteries due to its good performance, especially in the initial discharging stage. In order to fully understand its initial oxygen reduction reaction (ORR), in this work, oxygen and lithium adsorptions and initial ORR on the stoichiometric and reduced CeO2 surfaces were systematically investigated using density functional theory (DFT) calculations. Changes of free energy values and structure parameters of the intermediates and precursors of the initial ORR were also studied to identify the possible reaction paths. It was found that the oxygen atoms are preferably adsorbed on the reduced CeO2 surface, whereas the lithium atoms are preferably adsorbed on both stoichiometric and reduced CeO2 surfaces, therefore, there exists a strong adsorption at the site with high oxygen coordinations. The reduced CeO2 with the surface oxygen vacancies was identified as the most critical surface for the initial oxygen reduction reaction. The path with the lithium adsorption as the first step was identified as the most probable one. A Li3O2 precursor was identified as the most possible initial structure of the catalyst to start the discharging process

A novel electrode with multifunction and regeneration for highly efficient and stable symmetrical solid oxide cell

Authors acknowledge financial support from National Key Research & Development Project (2016YFE0126900), National Natural Science Foundation of China (51672095, U1910209), and China Scholarship Council (201806160178). The work is also partially supported by State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology (P2019-004).Symmetrical solid oxide cells (SSOCs) have been extensively recognized due to their simple cell configuration, low cost and reliability. High performance electrode is the key determinant of SSOCs. Herein, a multifunctional perovskite oxide La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCaFN) is investigated as electrode for SSOCs. The results confirm that LCaFN shows excellent oxygen reduction reaction (ORR), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2-RR) and hydrogen oxidation reaction (HOR) catalytic activity. In SOFC mode, the SSOCs with LCaFN achieve good electrochemical performance with maximum power density of 300 mW cm−2 at 800 °C. For pure CO2 electrolysis in SOEC mode, polarization resistance of 0.055 Ω cm2 and current density of 1.5 A cm−2 are achieved at 2.0 V at 800 °C. Besides, the cell shows excellent stability both in SOFC mode and SOEC mode. Most importantly, SSOCs with symmetrical LCaFN electrodes show robust and regenerative performance under anodic or cathodic process during the switching gas, showing the great reliability of the SSOCs. The results show that this novel electrode offers a promising strategy for operation of SSOCs.PostprintPeer reviewe

Boosting CO2 electrolysis performance : via calcium-oxide-looping combined with in situ exsolved Ni-Fe nanoparticles in a symmetrical solid oxide electrolysis cell

Financial support from National Key Research & Development Project (2016YFE0126900), National Natural Science Foundation of China (51672095), Hubei Province (2018AAA057) and the EPSRC Capital for Great Technologies Grant EP/L017008/1. We are grateful to the China Scholarship Council for funding (201806160178).The electrocatalysis of CO2 to valuable chemical products is an important strategy to combat global warming. Symmetrical solid oxide electrolysis cells have been extensively recognized for their CO2 electrolysis abilities due to their high efficiency, low cost, and reliability. Here, we produced a novel electrode containing calcium oxide-looping and in situ exsolved Ni–Fe nanoparticles by performing a one-step reduction of La0.6Ca0.4Fe0.8Ni0.2O3−δ (LCaFN). The CO2 captured by CaO was electrolyzed in situ by the Ni–Fe nanocatalysts. The cell with this special cathode showed a higher current density (0.632 A cm−2vs. 0.32 A cm−2) and lower polarization resistance (0.399 Ω cm2vs. 0.662 Ω cm2) than the unreduced LCaFN cathode at 800 °C with an applied voltage of 1.3 V. Use of the developed novel electrode offers a promising strategy for CO2 electrolysis.PostprintPeer reviewe

Pattern recognition of barely visible impact damage in carbon composites using pulsed thermography

This paper proposes a novel framework to characterise the morphological pattern of Barely Visible Impact Damage using machine learning. Initially, a sequence of image processing methods are introduced to extract the damage contour, which is then described by a Fourier descriptor-based filter. The uncertainty associated with the damage contour under the same impact energy level is then investigated. A variety of geometric features of the contour are extracted to develop an AI model, which effectively groups the tested 100 samples impacted by 5 different impact energy levels with an accuracy of 96%. Predictive polynomial models are finally established to link the impact energy to the three selected features. It is found that the major axis length of the damage has the best prediction performance, with an R2 value up to 0.97. Additionally, impact damage caused by low energy exhibits higher uncertainty than that of high energy, indicating lower predictability.Engineering and Physical Sciences Research Council (Grant Number: EP/P027121/1

BaCe0.8Fe0.1Ni0.1O3−δ-impregnated Ni–GDC by phase-inversion as an anode of solid oxide fuel cells with on-cell dry methane reforming

BaCe0.8Fe0.1Ni0.1O3−δ (BCFN) in a perovskite structure is impregnated consecutively by BCFN solution and BCFN suspension into a phase-inversion prepared NiO–Gd0.1Ce0.9O2−δ (GDC) scaffold as an anode for solid oxide fuel cells (SOFCs) with on-cell dry reforming of methane (DRM). The whole pore surface of the scaffold is covered by small BCFN particles formed by BCFN solution impregnation; the large pores near the scaffold surface are filled by BCFN aerogels with a high specific surface area produced by BCFN suspension impregnation, which act as a catalytic layer for on-cell DRM. After reduction, the anode consists of a Ni–GDC scaffold and BCFN particles with exsolved FeNi3 nanoparticles. This BCFN-impregnated Ni–GDC anode has higher electrical conductivity, electrochemical activity, and resistance to carbon deposition, with which the cell shows maximum power densities between 1.44 and 0.92 W·cm−2 when using H2 and between 1.09 and 0.50 W·cm−2 when using CO2–CH4 at temperatures ranging from 750 to 600 °C. A stable performance at 400 mA·cm−2 and 700 °C is achieved using 45% CO2–45% CH4–10% N2 for more than 400 h without carbon deposition, benefiting from the impregnated BCFN aerogel with a high specific surface area and water adsorbability

Fine Mapping of a Novel Heading Date Gene, TaHdm605, in Hexaploid Wheat

The heading date is critical in determining the adaptability of plants to specific natural environments. Molecular characterization of the wheat genes that regulate heading not only enhances our understanding of the mechanisms underlying wheat heading regulation but also benefits wheat breeding programs by improving heading phenotypes. In this study, we characterized a late heading date mutant, m605, obtained by ethyl methanesulfonate (EMS) mutation. Compared with its wild-type parent, YZ4110, m605 was at least 7 days late in heading when sown in autumn. This late heading trait was controlled by a single recessive gene named TaHdm605. Genetic mapping located the TaHdm605 locus between the molecular markers cfd152 and barc42 on chromosome 3DL using publicly available markers and then further mapped this locus to a 1.86 Mb physical genomic region containing 26 predicted genes. This fine genetic and physical mapping will be helpful for the future map-based cloning of TaHdm605 and for breeders seeking to engineer changes in the wheat heading date trait

Influence of orbital contributions to the valence band alignment of Bi2O3, Fe2O3, BiFeO3, and Bi0.5Na0.5TiO3

The formation of an interface between Bi2O3, Fe2O3, BiFeO3, Bi0.5Na0.5TiO3, and the high work function metallic RuO2 is studied using photoelectron spectroscopy with in situ RuO2 deposition. Schottky barrier heights are derived and the valence band maximum energies of the studied materials are aligned with respect to each other as well as to other functional oxides like SrTiO3 and PbTiO3. The energy band alignment follows systematic trends compared to a large number of oxides, and can be understood in terms of the contribution of Fe 3d and Bi 6s/6p (lone pair) orbitals to electronic states near the valence band maximum. The results indicate that the valence band maxima are largely determined by the local environment of the cations, which allows to estimate valence band maximum energies of oxides with multiple cations from those of their parent binary compounds. The high valence band maximum of BiFeO3 is consistent with reported p-type conduction of acceptor doped material, while the high conduction band minimum makes n-type conduction unlikely