Gas-Permeable Inorganic Shell Improves the Coking Stability and Electrochemical Reactivity of Pt toward Methane Oxidation

Synthesis of Highly Tunable Alloy Nanocatalyst through Heterogeneous Doping Method

The combination of supported metal nanoparticles and functional host oxides catalyze many major industrial reactions. However, uniform dispersion and ideal chemical configuration of such nanoparticles, which determines the catalytic activity, are often difficult to achieve. In this study, a unique combination is proposed of heterogeneous doping and ex-solution for the fabrication of Pt-Ni alloy nanoparticles on CeO₂ . By manipulating the reducing conditions, both the particle size and composition are precisely controlled, thereby achieving a highly dispersed and stable alloy nanocatalyst. The unique behavior of controlled alloy composition is elucidated through classical diffusion and precipitation kinetics with elemental analysis of the grain boundaries. Finally, Pt-Ni alloy nanocatalysts are successfully tuned showcasing a breakthrough performance compared to single element catalyst in reverse water gas shift reaction with superior stability and reproducibility.

Nanofiber Composites as Highly Active and Robust Anodes for Direct-Hydrocarbon Solid Oxide Fuel Cells

Direct utilization of methane fuels in solid oxide fuel cells (SOFCs) is a key technology to realize the immediate inclusion of such high-efficiency fuel cells into the current electricity generation infrastructure. However, the broad commercialization of direct-methane fueled SOFCs is critically hindered by the inadequate electrode activity and their poor longevity, which primarily stems from the carbon build-up issues. To make the technology more competitive, a novel electrode structure that can dramatically improve the tolerance against coking is essential. Herein, we present highly active and robust core-shell nanofiber anodes, La_0.75Sr_0.25Cr_0.5Mn_0.5O₃@Sm_0.2Ce_0.8O_1.9 (LSCM@SDC), directly obtained with a single-nozzle electrospinning process through the use of two immiscible polymers. The intimate coverage of SDC on LSCM not only increases the active reaction sites but also promotes resistance toward carbon deposition and thermal aggregation. As such, the electrode polarization resistance obtained with LSCM@SDC NFs is among the lowest value ever reported with LSCM derivatives (∼0.11 Ω cm² in wet H₂ at 800 °C). The facile fabrication process of such complex heterostructures developed in this work is attractive for the design of not only SOFC electrodes but also other solid-state devices such as electrolysis cells, membrane reformers, and protonic cells.

Influence of growth temperature on dielectric strength of Al2O3 thin films prepared via atomic layer deposition at low temperature

Thin films grown via atomic layer deposition (ALD) suffer from insufficient growth rate and unreliability for temperature-sensitive electronic substrates. This study aimed to examine the growth characteristics and dielectric strength of ALD Al₂O₃ films grown at low temperatures (≤ 150 °C) for potential application in flexible electronic devices. The growth rate of the Al₂O₃ films increased from 0.9 to 1.1 Å/cycle with increasing temperature and saturated at growth temperatures ≥ 150 °C, which is the critical temperature at which a complete oxidation reaction occurred. The dielectric strength was also improved with increasing growth temperature, and the films grown at 150 °C showed a high breakdown field strength (~ 8.3 MV/cm), attributable to the decrease in the carbon impurities and oxygen defects, as confirmed by X-ray photoelectron spectroscopy. Even at low growth temperatures (≤ 150 °C), ALD Al₂O₃ films showed an overall amorphous structure and extremely smooth surfaces regardless of the growth temperature.

Nanoscale interface engineering for solid oxide fuel cells using atomic layer deposition

Atomic layer deposition (ALD), which is already actively used in the semiconductor industry, has been in the spotlight in various energy fields, such as batteries and fuel cells, given its unique ability to enable the nanoscale deposition of diverse materials with a variety of compositions onto complex 3D structures. In particular, with regard to ceramic fuel cells, ALD has attracted attention because it facilitates the manufacturing of thin and dense electrolytes. Furthermore, recently, electrode surfaces and electrode/electrolyte interface modification are arising as new research strategies to fabricate robust fuel cells. In this mini-review, we present a brief overview of ALD and recent studies that utilize ALD in ceramic fuel cells, such as manufacturing thin film electrolytes, stabilizing electrodes, functionalizing electrodes, and modifying the chemistry of electrode surfaces. We also propose research directions to expand the utility and functionality of the ALD techniques.

Catalyst overcoating engineering towards high-performance electrocatalysis

Clean and sustainable energy needs the development of advanced heterogeneous catalysts as they are of vital importance for electrochemical transformation reactions in renewable energy conversion and storage devices. Advances in nanoscience and material chemistry have afforded great opportunities for the design and optimization of nanostructured electrocatalysts with high efficiency and practical durability. In this review article, we specifically emphasize the synthetic methodologies for the versatile surface overcoating engineering reported to date for optimal electrocatalysts. We discuss the recent progress in the development of surface overcoating-derived electrocatalysts potentially applied in polymer electrolyte fuel cells and water electrolyzers by correlating catalyst intrinsic structures with electrocatalytic properties. Finally, we present the opportunities and perspectives of surface overcoating engineering for the design of advanced (electro)catalysts and their deep exploitation in a broad scope of applications.

Status and prospects of the decentralised valorisation of natural gas into energy and energy carriers

We critically review the recent advances in process, reactor, and catalyst design that enable process miniaturisation for decentralised natural gas upgrading into electricity, liquefied natural gas, fuels and chemicals.