bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Flowerlike Ce1-XZrxO2-δ-Dispersed Paper-Structured Catalyst for Direct-Biogas SOFC
Authors: Tu Phuc Hoan , Sakamoto Mio , Sasaki Kanzunari , Shiratori Yusuke 
Published: July 2021

Performance of direct internal reforming (DIR)-solid oxide fuel cell (SOFC) can be improved by the application of the paper-structured catalyst (PSC) on the anode material. In the ceramic fiber network of the PSC, any kinds of functional materials can be easily dispersed during paper-making process.
The solid solution based on the equimolar mixture of ceria and zirconia (Ce0.5Zr0.5O2-δ), hereafter called CZ, is a promising oxide support of the Ni metal catalyst due to its high specific surface area and high oxygen storage capacity (OSC). By employing the two-step hydrothermal process developed in this study, we could successfully prepare the CZ with flowerlike geometry, which can prevent Ni from sintering under reducing atmosphere.
Ni-loaded PSCs with and without the dispersion of CZ, Ni/CZ-PSC and Ni-PSC, respectively, were prepared. Structures of the PSCs were characterized by X-ray diffractometry (XRD), BET specific surface area measurement, field emission scanning electron microscopy (FESEM), inductively coupled plasma spectrometry (ICP) and thermogravimetric analysis (TG). Catalytic performances of these PSCs for the dry reforming of methane (DRM) in the feed of the equimolar mixture of CH4 and CO2 were evaluated by an automatic gas chromatograph (GC) with the posttest analysis by FESEM observation, temperature-programmed oxidation (TPO) and TG to estimate carbon deposition.
In the durability (160 h) tests of the prepared-PSCs for DRM at 750oC under gas hourly space velocity (GHSV) of 2300 h-1 revealed that, for both cases with and without CZ dispersion, methane conversions were stable with the degradation rates (estimated after 10 h) of 13.7 and 21.8% 1000 h-1, respectively. TG measurements after the 160 h tests under oxidizing atmosphere in the range from 300 to 750oC revealed that the weights of the deposited carbon were 0.2 and 3.4 folds of those of PSCs for Ni/CZ-PSC and Ni-PSC, respectively. In the case without CZ dispersion (Ni-PSC), after the TG measurement to burn out the deposited carbon, Ni agglomeration and its detachment from the ceramic fiber could be clearly observed. On the other hand, for the Ni/CZ-PSC, these phenomena were considerably suppressed thanks to the flowerlike morphology for better dispersion of Ni metal particles and higher OSC of CZ solid solution to consume deposited carbon by the lattice oxygen.
The developed PSCs will be applied on the anode of electrolyte-supported cell to demonstrate the stable operation of DIR-SOFC fueled by biogas (direct-biogas SOFC).
Stability of Nickel/Scandia-Doped-Stabilized-Zirconia Composite Anode Under High Fuel Utilization Conditions
Authors: Taniguchi Shunsuke , Miyara Kengo , Kawabata Tsutomu , Uryu Chie , Inoue Yuko , Chou Jyh-Tyng , Sasaki Kazunari 
Published: July 2021

Microstructure change of nickel/scandia-doped-stabilized-zirconia (Ni/ScSZ) composite anode near the electrode reaction sites was investigated with increasing pH2O and current density. Electrolyte supported cell with ScSZ electrolyte was operated at 700oC under the gas composition of x%H2O-(50-x)%H2-50%N2. In the Ni/ScSZ anode, Sc dissolved into the adjacent Ni and concentrated at the center of the Ni particle. Dissolution of Sc from ScSZ was enhanced under high pO2 or high current density. Oxidation and reduction of Ni accompanied by the electrode reaction under such severity conditions affected microstructure of the Ni particles.
This research was supported by New Energy and Industrial Technology Development Organization (NEDO) on "Fundamental study for rapid evaluation method of SOFC durability".
Correlation Between Microstructure and Macroscopic Properties of Solid Oxide Fuel Cell Composite Anode: Mesoscale Modeling and Deep Learning with Convolutional Neural Network
Authors: Liu Xuhao , Zhou Shihao , Yan Zilin , Zhong Zheng , Shikazono Naoki , Hara Shotaro 
Published: July 2021

In this paper, we propose a framework for studying the linkage between microstructure and performance of Ni-YSZ anode in solid oxide fuel cells (SOFCs) by using meso-scale modeling and deep learning. The discrete element method (DEM) and the mesoscale kinetic Monte Carlo (KMC) method were respectively used to model the particle packing and sintering of composite Ni-YSZ anodes. Anodes with various microstructures were numerically synthesized by varying volume fraction, sizes and size distributions of solid phases and pores. Then, representative volume elements (RVEs) of anode microstructures were meshed for finite element modeling of the effective elastic modulus and thermal coefficient of expansion of the anode based on the homogenization theory. The triple phase boundary length density (
L

TPB), tortuosity factor for each phase were also calculated based on RVEs.
Based on a large dataset which consists of various anode microstructures (represented as ternary image stacks) and corresponding macroscopic properties, a deep convolutional neural network (CNN) was trained to capture the nonlinear functional relationship between anode microstructures and macroscopic properties. The deep learning CNN model was finally well validated against extra new samples with excellent predictive performances. This indicates that the CNN model can be used as a surrogate model for rapid direct access to macroscopic properties of composite anodes, if the microstructure of the anode is known. The macroscopic properties can be further used for continuum modeling of SOFCs.
This framework is highly extendable for other single-phase or composite electrodes of SOFCs. In addition, the proposed framework provides a new ideal for multiscale and multiphysics modeling of SOFCs.
Experimental Investigation of an Anode Supported SOFC Stack Under High Direct Internal Reforming Conditions
Authors: Hauck Maximilian , Herrmann Stephan , Fischer Felix , Weinrich Jeremias , Steinrücken Benjamin , Spliethoff Hartmut 
Published: July 2021

Direct internal reforming (DIR) of hydrocarbons like methane can help improve both economics and efficiency of solid oxide fuel cell (SOFC) systems. The endothermic reforming reaction yields chemical energy in form of hydrogen by directly utilizing waste heat from the cells, which is more efficient than other concepts like partial oxidation (POX) of the fuel gas. Furthermore, DIR cools the stack, reducing the need for excess air. The parasitic power consumption of the air blower is reduced, as well as investment costs for blowers and external reformers. However, DIR can potentially damage SOFC stacks due to thermal gradients and resulting stresses. Furthermore, in case of natural gas, usually some degree of external reforming is needed to convert heavy hydrocarbons like ethane, since these would cause carbon depositions on the SOFC anode.
In this paper, we present experimental data from the operation of an anode supported short stack from Ningbo SOFCMAN Energy Technology. Natural gas was used as fuel, and the stack was operated under varying degrees of DIR. The reforming level was adjusted using an electrically heated reformer, and monitored with an online gas analysis. Up to 90 % internal reforming has been demonstrated without signs of carbon deposition or cell fracture. Increasing the degree of DIR had a moderate adverse effect on the stack performance. Possible reasons for this behavior are discussed.
These results show that operation of stacks from Ningbo SOFCMAN Energy Technology under high degrees of DIR is feasible, while some performance decrease has to be expected.
Degradation Analysis of SOFC Performance for Long-Term Operation with High Fuel Utilization
Authors: Ido Akifumi , Imabayashi Takumi , Asano Koichi , Yamamoto Tohru , Morita Hiroshi , Mugikura Yoshihiro 
Published: July 2021

A national project in Japan for SOFC development has been initiated from FY2020 to FY2024 in NEDO’s project in order to establish the method for degradation diagnosis of SOFC stacks with durability and reliability for 130,000 hours or the method for evaluation of expanding application. Central Research Institute of Electric Power Industry (CRIEPI) has operated three types of SOFC stacks, which are developed by KYOCERA, MORIMUA SOFC TECHNOLOGY, and DENSO and investigated their long-term durability in this project.
We have developed the electrode polarization model for SOFC performance which is able to express the SOFC performance such as Nernst loss, cathode overvoltage, anode overvoltage, and internal resistance (IR) loss under various conditions with high prediction accuracy. Each SOFC stack has been operated with high fuel utilization (Uf = 80% and 85%) as a severe condition for high efficiency towards 20,000-hours operation, and degradation factors for SOFC durability has been analyzed by using our electrode polarization model. Analysis results until now showed that dominant degradation factors for both Uf = 80% and 85% were increase of cathode overvoltage or IR loss as same as that of the SOFC stacks in the previous term [1]. Although anode overvoltage was a minor degradation factor, increase rate of anode overvoltage under Uf = 85% was relatively larger than that under Uf = 80%.
In addition, thermal property testing will be conducted for each SOFC stack in order to include temperature term into our electrode polarization model. This new model can predict SOFC performance more accurately under various operating conditions.
This work has been carried out under the project of the New Energy and Industrial Technology Development Organization (NEDO), Japan as a contract research. We would like to express our gratitude to NEDO, KYOCERA, MORIMUA SOFC TECHNOLOGY, Denso as well as to university partners and National Institute of Advanced Industrial Science and Technology (AIST).
Reference
[1] A. Ido et al., ECS Transactions, 91(1), 801-808 (2019).
Electrochemical Performance of Pr0.8Ca0.2Fe0.8Co0.2O3-δ as Air Electrode for Reversible Solid Oxide Cells
Authors: Li Yitong , Tian Yunfeng , Chi Bo , Pu Jian 
Published: July 2021

Energy and environmental issues have always been topics of great concern to the world in recent years. The production of electricity from solar and wind energy has increased dramatically. These significant developments in renewable energy technologies are now driving the development of a method to efficiently store and transport the inherently intermittent electricity from these natural resources [1]. Under this situation, the emergence of reversible solid oxide cells (RSOCs) has been attracted widespread attention. As a clean and efficient electrochemical conversion device, RSOCs can link electrical and chemical energy and convert flexibly, which is of great significance for power generation and energy storage [2]. It can operate in two modes: (i) as solid oxide fuel cells (SOFCs) for power production and (ii) as solid oxide electrolysis cells (SOECs) for hydrogen and oxygen production [3].
Herein, we successfully synthesized a novel perovskite Pr0.8Ca0.2Fe0.8Co0.2O3-
δ and used it as an air electrode in reversible solid oxide cells. In the SOFCs mode, the peak power density is up to 1.056 W cm-2 at 850 ºC using hydrogen as the fuel and air as the oxidant. It can achieve 1.43 A cm-2 at 850 ºC under an operating voltage of 1.3 V in the SOECs mode with water content of 50%. Moreover, the cell can run stably in both SOFCs and SOECs modes with showing excellent reversibility. During a short-time reversible term, it remains both electrochemical performance and structure stable. These results demonstrate that the perovskite Pr0.8Ca0.2Fe0.8Co0.2O3-
δ is promising air electrode for applications in RSOCs.

References

[1] Choi S, Davenport T C, Haile S M. Protonic ceramic electrochemical cells for hydrogen production and electricity generation: exceptional reversibility, stability, and demonstrated faradaic efficiency. Energy & Environmental Science, 2019, 12(1): 206-215.
[2] Y. Luo, Y. Shi, Y. Zheng, N. Cai, Reversible solid oxide fuel cell for natural gas/renewable hybrid power generation systems, J Power Sources, 340 (2017), pp. 60-70.
[3] Meng X., Liu Y., Yang N., Tan X., Liu J., J.C. Diniz da Costa, Liu S. Appl. Energy, 205 (2017), pp. 741-748
Simulation of a Flat-Tube Solid Oxide Fuel Cell with Symmetric Double-Sided Cathode Considering Different Fuel Compositions
Authors: Zhang Xiaoqiang , Espinoza Andaluz Mayken , Wang Lei , Li Tingshuai , Andersson Martin 
Published: July 2021

Due to its high operating temperature, solid oxide fuel cells (SOFCs) can use a variant of hydrocarbon fuels. Then the methane steam reforming (MSR) and water gas shift (WGS) reactions are active within the anode during the energy conversion process. On one hand, the air velocity controls the heat within a SOFC, e.g., through control of heat convection, on the other hand, the internal endothermal reactions also have an impact on the heat balance through different fuel composition. It should be noted that the carbon deposition greatly reduces the catalytic property of the anode material.
The reforming process can be synthetized by the following electrochemical reactions:
2CO ↔ C(s)+ CO2 (1)
CO+H2 ↔ C(s)+H2O (2)
C
n
H2n+2 ↔ nC(s)+(n+1)H2 (3)
Thus, it is important to investigate the effect of internal reforming reactions of different fuel composition on cell performance.
Numerical simulations can reduce the cost of experimental design and achieve desirable accuracy. A flat-tube SOFC with a symmetric double-sided cathode is built using the commercial software COMSOL Multiphysics®. Our model includes the simulation of the ion, electron, momentum, heat, and mass transport phenomena. Also, MSR and WGS reactions are considered in the model. The geometric representation of the flat-tube SOFC anode is shown in Figure 1.

Figure 1
Recent Achievement of Degradation Analyses in Japanese National Project: High Efficiency and Dynamic Operation Effects on the Durability of SOFC Stacks
Authors: Horita Teruhisa 
Published: July 2021

To achieve high efficiency of 65% LHV in the solid oxide fuel cells (SOFCs), the fuel utilization should increase to the level of over 80%, which is 10-15% higher fuel utilization (Uf) than the standard condition, and severe degradation can occur at the component materials. When the current density is controlled in the stack level, there might be the distribution of fuel utilization in the cells due to the distribution of fuel gas, water vapor pressures, and temperatures. So far, many studies were examined on the clarification of degradation mechanism under fuel cell operation.
In this report, recent achievements of the Japanese national projects (NEDO projects) are presented, especially on the rapid evaluation methods for degradation (2018-2019) and most recent “Development of advanced evaluation and analysis technologies for the durability of Solid Oxide Fuel Cells stacks (2020-)”. Especially, the anode durability was discussed with different kinds of cell-stack geometry at high fuel utilization. The degradation mechanism and fuel utilizations are compared at the planer and flat tubular type cell-stacks. We discussed the microstructure change and stability of the Ni-YSZ cermet anode at high Uf and current density conditions.
Electro-Chemo-Mechanical Failure in a High-Performance Solid Oxide Cell
Authors: Lenser Christian , Zhang Jun , Russner Niklas , Weber Andre , Guillon Olivier , Menzler Norbert 
Published: July 2021

Fuel electrode-supported solid oxide cells (FE-SOC) offer the possibility of low operation temperatures and / or high power density through the incorporation of a thin, supported electrolyte between two highly active electrodes. However, integrating fuel electrodes with an ionic conductor that is different from that of the electrolyte into FE-SOC remains a challenge due to the interdiffusion phenomena during co-sintering of the half-cell. As a result, most FE-SOC use cermet fuel electrodes made from Ni and stabilized zirconia.
Here, we present a FE-SOC based on a Ni-Gd0.1Ce0.9O2-
d (GDC) fuel electrode, a three-layer GDC / zirconia / GDC electrolyte and an La0.58Sr0.4CoO3-
d (LSC) air electrode. The electrolyte is fabricated by co-sintering a thin, screen-printed layer of GDC with the fuel electrode and support. Subsequent electrolyte layers are deposited via physical vapor deposition (PVD), and the air electrode is fabricated via screen printing. The total electrolyte thickness is less than 5 µm, enabling an area-specific ohmic resistance < 10 mΩ cm² at 700 °C. A current density of 1.6 Acm-² is achieved at a cell voltage of 800 mV and a temperature of 700 °C, using 10% H2O/H2 as fuel and air as oxidant. This performance is about twice as high as that of a conventional Jülich cell using Ni-YSZ and LSCF electrodes and a 10 µm YSZ electrolyte under similar conditions. An electrolysis current of 2 A cm-² was achieved at a cell voltage of 1.11 V, at a temperature of 800 °C and using 50% H2O/H2 and air. The conventional Jülich cell requires a cell voltage above 1.25 V under similar conditions. Under these conditions, the new cell achieves a cell efficiency of 84 %, compared to 73 % for the conventional cell.
However, running high electrolysis currents at temperatures below 750 °C resulted in catastrophic cell failure, visible as large voltage jumps in the I-V curve. In addition, a decreasing OCV value with decreasing temperature indicated damage to the cell before the catastrophic failure. Post-test analysis found a large number of cracks in the electrolyte, nucleating at the fuel electrode / electrolyte interface and running toward the air electrode. We show that the likely cause for this failure is the electrochemical reduction and subsequent chemical expansion of the doped ceria electrolyte layer, necessitating a detailed study of the local mechanical stresses in the cell during operation.
N-Doped Biochar as H2s Adsorbent for the Biogas-Fueled SOFC
Authors: Setiawan Hendrik , Sakamoto Mio , Shiratori Yusuke , Fujisaki Takaya 
Published: July 2021

Reliability of biogas-fueled SOFC is tied directly to the purity of biogas used as fuel. Even miniscule amount of H2S can poison the anode material and drastically shorten the operation time of biogas-fueled SOFC. In order to prevent the performance degradation caused by H2S poisoning, the aim of this study is to develop an attractive process to obtain a nitrogen (N)-doped carbon derived from biomass feedstock using the digested liquid as a source of N, which can act as an excellent adsorbent material to reduce the H2S concentration in biogas below sub ppm level.
Rice husk (RH) was pyrolyzed at 500oC for 2 h under O2-free atmosphere to produce biochar (BC). Rice husk biochar (RH-BC) was then treated with ammonia gas (25% NH3) at 500 or 900°C for 2 h (Intense N-doping) to have N-doped RH-BC (RH-BC(N500-120) and RH-BC(N900-120)). 10% NH3 solution was prepared to simulate the concentrated ammonia solution obtained from the digested liquid discharged from the methane fermentation reactor. The 10% NH3 solution was heated at 30oC through which 100 mL min-1 N2 was passed to obtain the vaporized NH3. RH-BC was treated with the NH3 vapor at 850°C for 90 or 270 min (Mild N-doping) to have N-doped RH-BC (RH-BC(EN850-90) and RH-BC(EN850-270)). Aiming at increasing the total H2S adsorption capacity (ACPH2S
), prior to the mild N-doping, pre-treatment of RH-BC with 15 vol% steam was performed at 850°C for 90 min (RH-BC(S850-90 + EN850-90)).
Specific surface area (SSA) of the porous RH-BC was 146 m2 g-1. By the NH3 treatment of the RH-BC, pyridinic-like N can be doped on the surface contributing to the formation of the oxygen radicals to consume H2S, leading to the enhancement of the ACPH2S
. RH-BC(N900-120) exhibited the highest breakthrough capacity (APCH2S(0)
) of 8.02 mg H2S g-BC-1 and ACPH2S
of 9.58 mg H2S g-BC-1. However, the highest ACPH2S
, 25.6 mg H2S g-BC-1, was obtained for RH-BC(S850-90 + EN850-90), while its APCH2S(0)
was 3.64 mg H2S g-BC-1.
XPS analysis revealed that, during the H2S adsorption, intense N-doping (RH-BC(N900-120)) resulted in the larger amount of sulfate formation on the surface compared to the mild N-doping (RH-BC(S850-90 + EN850-90)). Abundance of oxygen radicals on the surface is preferable for the sulfate formation. This explains the high ACPH2S(0)
of the intensely N-doped sample, RH-BC(N900-120). On the other hand, for the mildly N-doped sample, RH-BC(S850-90 + EN850-90), interaction of the surface with H2S was moderately weakened to avoid the blocking of the micropore openings with sulfate, which enables the H2S molecules to adsorb into the micropores, resulting in the higher ACPH2S
.
Substrate Characterization and Outcomes of Ventricular Tachycardia Ablation in
TTN (Titin)
Cardiomyopathy
Authors: Enriquez Andres , Liang Jackson , Smietana Jeffrey , Muser Daniele , Salazar Pablo , Shah Rajan , Badhwar Nitish , Bogun Frank , Marchlinski Francis , Garcia Fermin , Baranchuk Adrian , Tung Roderick , Redfearn Damian , Santangeli Pasquale 
Published: July 2021

Background:

Truncating variants of the
TTN
(
titin
) gene are a leading cause of dilated cardiomyopathy and have been associated with an increased risk of ventricular arrhythmias. This study evaluated the substrate distribution and the acute and long-term outcomes of patients with
TTN
-related cardiomyopathy undergoing ventricular tachycardia (VT) ablation.

Methods:

This multicenter registry included 15 patients with dilated cardiomyopathy (age, 59±11 years; 93% men; ejection fraction, 30±12%) and genotypically confirmed truncating variants of the
TTN
gene who underwent VT ablation between July 2014 and 2020.

Results:
All patients presented with sustained monomorphic VT, including electrical storm in 4 of them. A median of 2 VTs per patient were induced during the procedure (cycle length, 318±68 ms), and the predominant morphologies were left bundle branch block with inferior axis (39%) and right bundle branch block with inferior axis (29%). A complete map of the left ventricle was created in 12 patients and showed voltage abnormalities mainly at the periaortic (92%) and basal septal regions (58%). A preprocedural cardiac magnetic resonance imaging was available in 13 patients, and in 11, there was evidence of left ventricular delayed gadolinium enhancement, with predominantly midmyocardial distribution. Sequential ablation from both sides of the septum was required in 47% of patients to target septal intramural substrate, and epicardial ablation was performed in 20%. At the end of the procedure, the clinical VT was noninducible in all patients, while in 3 cases, a nonclinical VT was still inducible. After a follow-up of 26.5±23.0 months, 53% of patients experienced VT recurrence, 20% received transplant or mechanical circulatory support, and 7% died.

Conclusions:

The arrhythmogenic substrate in
TTN
-related cardiomyopathy involves the basal septal and perivalvular regions. Long-term outcomes of catheter ablation are modest, with high recurrence rate, likely related to an intramural location of VT circuits.