Proton exchange membrane fuel cells (PEMFCs) have garnered significant attention due to their high efficiency and low emissions. However, PEMFC always suffers mass transfer and water management in performance improvement. Herein, an integrated gas diffusion layer (GDL) with wavy channel and micro-tunneled rib is designed and prepared to achieve faster and gentler mass transfer and excellent water management capability by laser engraving.
View Article and Find Full Text PDFIn this work, an ordered membrane electrode assembly (MEA) based on a cone Nafion array with gradient Nafion distribution, tightly bonded catalytic layer/proton exchange membrane (CL/PEM) interface, and abundant vertical channels has been engineered by an anodic aluminum oxide template and magnetron sputtering method. Benefiting from a highly efficient CL/PEM interface, plentiful proton transfer highways, and rapid oxygen bubble release, this ordered MEA achieves an ultralow Ir loading of 20.0 μg cm and a high electrochemical active area by 8.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2023
Hierarchically patterned proton-exchange membranes (PEMs) have the potential to significantly increase the specific surface area, thus improving the catalyst utilization rate and performance of proton-exchange membrane fuel cells (PEMFCs). In this study, we are inspired by the unique hierarchical structure of the lotus leaf and proposed a simple three-step strategy to prepare a multiscale structured PEM. Using the multilevel structure of the natural lotus leaf as the original template, and after structural imprinting, hot-pressing, and plasma-etching steps, we successfully constructed a multiscale structured PEM with a microscale pillar-like structure and a nanoscale needle-like structure.
View Article and Find Full Text PDFThe use of ordered catalyst layers, based on micro-/nanostructured arrays such as the ordered Nafion array, has demonstrated great potential in reducing catalyst loading and improving fuel cell performance. However, the size (diameter) of the basic unit of the most existing ordered Nafion arrays, such as Nafion pillar or cone, is typically limited to micron or submicron sizes. Such small sizes only provide a limited number of proton transfer channels and a small specific area for catalyst loading.
View Article and Find Full Text PDFThe commercialization of fuel cells inevitably brings recycling problems. Therefore, achieving high recyclability of fuel cells is particularly important for their sustainable development. In this work, a recyclable standalone microporous layer (standalone MPL) with interpenetrating network that can significantly enhance the recyclability and sustainability of fuel cells is prepared.
View Article and Find Full Text PDFDeveloping high-performance catalysts for fuel cell catalysis is the most critical and challenging step for the commercialization of fuel cell technology. Here 1D trimetallic platinum-iron-cobalt nanosaws (Pt FeCo NSs) with low-coordination features are designed as efficient bifunctional electrocatalysts for practical fuel cell catalysis. The oxygen reduction reaction (ORR) activity of Pt FeCo NSs (10.
View Article and Find Full Text PDFSmaller volume/weight and higher output power/energy density are always the goals of electrochemistry energy devices. Here, a simple strategy is proposed to prepare an integrated gas diffusion electrode (GDE) with high conductivity through skin electroplating. The skin electroplating is the combination of magnetron sputtering and spatial confinement electroplating.
View Article and Find Full Text PDFPure oxygen is vital in medical treatment, first aid, and chemical synthesis. Hypoxia can cause severe damage to the organ systems such as respiratory, digestive, and nervous systems and even directly cause death. Notably, the severe Coronavirus disease 2019 (COVID-19) pandemic has exacerbated the shortage of medical oxygen in the world.
View Article and Find Full Text PDFHydrogen is one of the most promising sustainable energy carriers for its high gravimetric energy density and abundance. Nowadays, hydrogen production and storage are the main constraints for its commercialization. As a current research focus, hydrogen production from methanol-water reforming, especially at low temperature, is particularly important.
View Article and Find Full Text PDFAs a clean and sustainable source of energy, hydrogen shows great potential to be the ultimate energy source in future. In this research, paraformaldehyde is used as hydrogen carrier. Several bifunctional catalysts are prepared for the hydrogen generation from paraformaldehyde.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2020
A proton exchange membrane fuel cell (PEMFC) system with a hydrogen generator could have higher energy density than flexible batteries and supercapacitors and is possible to meet the urgent demand of flexible electronics. However, a flexible PEMFC pack is still not available due to the absence of a flexible hydrogen generator. To solve this problem, we successfully invented a flexible and adaptable hydrogen generator, which was realized by a new bifunctional aerogel catalyst with the abilities of both storing and producing hydrogen.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2018
It is a great challenge to fabricate a metal-free oxygen reduction reaction (ORR) electrocatalyst that can operate well in the acidic medium and fuel cells system. Here, a metal-free carbon material C-900 with abundant defect sites is fabricated by a self-sacrificed template and a solid-state reaction strategy. C-900 shows a superior performance to 20% Pt/C in alkaline medium and a performance closer to 20% Pt/C in acidic condition.
View Article and Find Full Text PDFAs an excellent hydrogen-storage medium, methanol has many advantages, such as high hydrogen content (12.6 wt %), low cost, and availability from biomass or photocatalysis. However, conventional methanol-water reforming usually proceeds at high temperatures.
View Article and Find Full Text PDFAs a promising hydrogen storage medium methanol has many advantages such as a high hydrogen content (12.5 wt%) and low-cost. However, conventional methanol-water reforming methods usually require a high temperature (>200 °C).
View Article and Find Full Text PDFGas-generating catalysis is important to many energy-related research fields, such as photocatalytic water splitting, water electrolysis, etc. The technique of single-nanoparticle catalysis is an effective way to search for highly active nanocatalysts and elucidate the reaction mechanism. However, gas-generating catalysis remains difficult to investigate at the single-nanoparticle level because product gases, such as H and O, are difficult to detect on an individual nanoparticle.
View Article and Find Full Text PDFFlexible devices have been attracting great attention recently due to their numerous advantages. But the energy densities of current energy sources are still not high enough to support flexible devices for a satisfactory length of time. Although proton exchange membrane fuel cells (PEMFCs) do have a high-energy density, traditional PEMFCs are usually too heavy, rigid, and bulky to be used in flexible devices.
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