High-performance and durable alcohol-fueled symmetrical solid oxide fuel cell based on ferrite perovskite electrode

This work is supported by the NSFC (grant No. 51702264; 41371275) and National Key Research and Development Program of China (grant No. 2018FYD0200701) and research funding for central universities (XDJK2020B066). C.N. also thanks to the award of Chongqing Bayu Young Scholar from Chongqing Teaching Committee and Funding for Oversea Returnees, while J.N. thanks to the support from Chongqing Yingcai Talent.A solid oxide fuel cell utilizing bio-fuels such as methanol and ethanol could provide a carbon–neutral electricity generation and facilitate its applications in transport or stationary power unit. Herein, Ce4+ doping in SrFe0.95Ni0.05O3 imparts FeNi3 exsolution and CeO2 precipitation in a reducing condition, contributing to the fuel reforming, C-C bond cleavage and coke consumption in the anode chamber. The ferrite perovskites are stable in ethanol/steam at 800 °C, whereas they are unstable in ethanol vapor with the high C fugacity inducing the formation of Fe0 and carbides. However, the Ce0.2Sr0.8Fe0.95Ni0.05O3 anode maintains mostly the perovskite and is free from coke after the 300 h’ operation under C2H5OH fuel at 0.5 V or 0.7 V because of the dynamic balance between the carbon deposition and consumption since an operation for 10 h shows a clear carbon deposition. A maximum power density of 0.58 W cm−2 and a polarization resistance of 0.21 Ω cm2 at 800 °C can be obtained for the symmetrical solid oxide fuel cell with identical Ce0.2Sr0.8Fe0.95Ni0.05O3 cathode and anode under an ethanol fuel. The results demonstrate that the reversible and stable SrFeO3 with Ce/Ni co-doping has a bright prospect for alcohol fuel oxidation.PostprintPostprintPeer reviewe

Modelling Fertilizer Use in Relation to Farmers’ Household Characteristics in Three Gorges Reservoir Area, China

Non-point source pollution from excessive use of fertilizers in agriculture is a major cause of the eutrophication problem in China. Understanding farmers’ decision-making concerning fertilization and identifying the influencing factors in this process are key to tackling overfertilization and related pollution issues. This paper reports a study on modelling decisions about fertilizer use based on data collected from 200 farmer households in the Three Gorges Reservoir area of China, using a well-fitted artificial neural network (ANN) with incorporated variance-based sensitivity analysis. The rate of fertilizer use estimated from the model is in good agreement with observed data. The model is further validated and tested by comparing the simulated and observed values. Results show that the model is able to identify the influencing factors and their interactions causing the variation in fertilizer use and to help pinpoint the underlying reasons. It is found that the farmers’ fertilization behavior is greatly affected by the area of cultivated land, followed by the interaction among farmers’ education level, annual income, and awareness of the importance of environmental protection. Future land consolidation is one of several ways to achieve more sustainable fertilization strategies

Evolution of Anodic Product from Molybdenum Metal in Absolute Ethanol and Humidity Sensing under Ambient Conditions

Authors would like to thank the support from National Natural Science Foundation of China (NSFC) (Nos. 51702264 and 41371275), Fundamental Research Funds for the Central Universities (No. XDJK2017B033), and Research Funding of Southwest University (No. SWU117019). The funding from the Engineering and Physical Sciences Research Council (EPSRC) (under Grant Nos. EP/K022237/1, EP/K036769/1, and EP/M024938/1) is also acknowledged. We also appreciate the funding from the EU COST Action (No. TD1208) for useful exchanges and discussions.Room-temperature nonaqueous synthetic routes turn out to be particularly competitive among all the available liquid-phase synthetic methods for nanometer-sized metal oxides for multiple applications. Microplasma-assisted anodization is employed to prepare soluble and crystalline Mo species in a water-deficient and extraneous ionic-salt-free ethanol electrolyte. The anodization of Mo in absolute ethanol is found to produce Mo oxyethoxide in the liquid ethanol phase, along with a small montage of mixed hexagonal and orthorhombic MoO3 crystals. The evolution of Mo species in solid and liquid phases is characterized to study the crystallization of MoO3 crystal and the formation of blue spherical Mo polyoxometalates (POMs) after extended aging. The addition of water in the suspension delayed the formation of molybdenum blue while hydrogen peroxide induced the precipitation of a dendritic framework of hexagonal MoO3. A thin MoO3 film was produced from the solution and can be used for humidity sensing by the facile conductivity measurement.PostprintPostprintPeer reviewe

The Comprehensive Management Zoning of Mountains, Rivers, Forests, and Farmlands Based on Element Recognition

Land subsidence, soil erosion, and landscape fragmentation frequently occur in regions of backward production capacity. Therefore, it is imperative to carry out efforts for ecological restoration in these mine-closed regions. The proposal of holistic conservation of mountains, rivers, forests, farmlands, lakes, grasslands, and deserts provides important guidance for ecological restoration. To support the governance of regional ecology, this paper aims to discuss the layout of element governance zoning in four southern towns of Qijiang District, Chongqing. SBAS-InSAR technology, vulnerability assessment, linear trend analysis, and suitability evaluation were used to divide the mountain, water, forest, and farmland management areas. Regional comprehensive management work was implemented according to the severity of each element’s existing ecological questions. Eventually, a comprehensive management pattern of mountains, rivers, forests, and farmlands can be obtained. The results show that the mountain management area is 8.03 km2 (3.24% of the total management area), the hydrological management area is 212.07 km2 (85.80% of the total management area), the forest management area is 7.04 km2 (2.84% of the total management area), and the farmland management area is 20.07 km2 (8.12% of the total management area). In light of the current circumstances, this study advocates for the implementation of three integrated governance approaches, with a focus on managing hydrological factors. These approaches include ridge-based mountain, water, and forest governance, valley-based mountain, water, and farmland governance, and undergrowth economy-based water, forest, and farmland governance. This study explores the spatial layout and priority of the governance areas from the perspective of elements, which provides a new development direction for the current research on the life community based on policy analysis

Evaluation and Factor Analysis of Industrial Carbon Emission Efficiency Based on “Green-Technology Efficiency”—The Case of Yangtze River Basin, China

In the context of low-carbon development, effectively improving carbon emission efficiency is an inevitable requirement for achieving sustainable economic and social development. Based on panel data of 11 provinces and municipalities in the Yangtze River Basin (YRB), ranging from 2000 to 2019, this paper uses green-technology efficiency to measure industrial carbon emission efficiency via stochastic frontier analysis (SFA) incorporated with carbon productivity. This provides a comprehensive analytical framework for assessing the carbon emission efficiency, quantitatively measuring the reduction potential, and clarifying the incentive channels. The results are as follows: (1) The industrial carbon emission efficiency (ICEE) of YRB presents an increasing trend. Although differences in emission efficiency among provinces and municipalities are narrowing, their emission efficiency is still prominently imbalanced. (2) The potential for reducing industrial carbon emissions in this region shows an upward-to-downward trend. The decline in such potential of each province and municipality in recent years indicates that further reduction is becoming more difficult. (3) Effective means to improve ICEE are to improve the level of industrialization, promote technological innovation in industrial low-carbonization, and raise industrial productivity. Meanwhile, the significant spatial spillover effect of ICEE further emphasizes the necessity of strengthening the coordination of carbon reduction policies in YRB. The research in this paper adds a new perspective to the evaluation of ICEE and also provides reference and technical support for the government to enhance ICEE and formulate green and sustainable development policies

α-PbO₂-type niobate as efficient cathode materials for steam and CO₂ electrolysis

α-PbO2-type Mn0.5Ti0.5NbO4-based oxides are studied as cathode materials in solid oxide electrolysis cell (SOEC) for the direct electrolysis of steam or CO2 at 800 °C. Comparison between Mn0.5Ti0.5NbO4 and the Fe-doped ones, Fe0.3Mn0.35Ti0.35NbO4 and Fe0.6Mn0.2Ti0.2NbO4, indicates that the Fe3+ doping increases the electric conductivity in air but decreases the stability of the α-PbO2 structure in reducing atmosphere as in Fe0.6Mn0.2Ti0.2NbO4. The electric conductivity in reducing atmosphere is found to be ascribed to Ti4+-O-Ti3+ and Fe3+-O-Fe2+ in Mn0.5Ti0.5NbO4 and Fe doped ones, respectively. The steam or CO2 electrolsysis indicates that 30% Fe3+ substitution for Mn/Ti decreases the polarization resistance at low bias, but 60% Fe doping increases the polarization resistance dramatically than Mn0.5Ti0.5NbO4. The excessive Fe3+ doping is found to induce the phase transformation and delamination on the cathode/electrolyte interface under a cathodic current. The electrolyser with Fe0.3Mn0.35Ti0.35NbO4 cathode on zirconia-based electrolyte imparts a stable current density of 2.32 Acm−2 at −1.6 V if Ar-88% H2O is used as feeding gas. Analysis of the gas product indicates that H2 is produced and the Faradaic efficiency at −1.4 V and −1.6 V is found to be 100% and 93%, respectively