Summary Chemical looping using methane offers the potential for producing syngas or hydrogen with intrinsic separation of CO2. An ilmenite (FeTiO3)‐based oxygen carrier is a suitable oxygen carrier for methane oxidation because of good reactivity and low cost. However, it underwent a phase separation during repeated redox cycles, thereby resulting in the decrease in the reactivity. Therefore, it is necessary to develop a TiO2‐supported iron oxide composite with high redox stability and reactivity. In this study, we synthesize a titania‐doped YSZ (Y0.20Ti0.15Zr0.65O1.90)‐promoted iron‐based oxygen carrier. Inert material (ZrO2), pure ionic material (YSZ), and electronic conductive material (TiO2) are used as support materials for comparison. It is found that the Y0.20Ti0.15Zr0.65O1.90 promotes iron‐based oxygen carrier showed the best performance (27%/min to achieve 66% conversion) in methane oxidation in TGA experiment, high syngas selectivity in fixed bed reactor, and the redox stability over 100 redox cycles. Meanwhile, the other oxygen carriers show low reactivity and the morphological changes (iron oxide layer) and/or the phase decomposition (ie, YSZ → Y2O3 and ZrO2 and Fe2TiO5 → Fe2O3 and TiO2). The enhanced reactivity and stability are mainly ascribed to the mixed ionic‐electronic conductivity and the redox stability of titania‐doped YSZ in the single‐phase fluorite region.

Correlating ex-situ measurements of Pt coverage using the thin film-rotating disk electrode (TF-RDE) and in-situ performance of proton exchange membrane (PEM) type fuel cells and electrolyzer is established. The TF-RDE has a smaller geometric electrode area, and, typically, lower Pt loading is used compared to the in-situ single cell of PEMs. The model equation for Pt contamination by adsorption mechanisms followed by dimensionless analysis enables us to find three important dimensionless groups, which has been shown to control the contamination phenomena. The capacity ratio of Pt loading and inlet concentration of the contaminant, the measure of the rate of reaction, and the coverage ratio of the contaminant is used to translate ex-situ to in-situ by providing the scaling factor that is key to the correlation. These scales lead to the prediction of the coverage on the Pt sites using the ex-situ adsorption isotherm. Also, dimensionless numbers are tested in in-situ performance tests of PEM fuel cells for validation.

Alkaline diaphragm water electrolysis (ADWE) devices are the most widely commercialized water splitting cells for large-scale applications. They are inexpensive and durable, but they undergo numerous voltage loss mechanisms that are absent in ion-exchange cells.1 Computational studies enable us to understand these losses and to engineer components that diminish them. Hammoudi et al.2 developed a validated one-dimensional multi-physics model incorporating bubble effects and compared relative overpotentials at different temperatures. Abdin et al.3 used a multi-physics approach that included electrode and separator properties to show effects of design parameters on performance. Our aim is to utilize computational fluid dynamics techniques to build an ADWE model that enables us to effectively engineer the flow field and porous transport layer (PTL). This two-phase model considers losses due to the presence of bubbles in the electrolyte, bubbles on the electrode surface, and shunt current through the diaphragm. We include a discussion of the current distribution in a straight channel ADWE device and what factors are important to consider for optimizing productivity and efficiency. References: M. Schalenbach et al., Journal of The Electrochemical Society, 163, F3197–F3208 (2016). M. Hammoudi, C. Henao, K. Agbossou, Y. Dubé, and M. L. Doumbia, International Journal of Hydrogen Energy, 37, 13895–13913 (2012). Z. Abdin, C. J. Webb, and E. M. A. Gray, Energy, 138, 316–331 (2017).