Nature-inspired optimization of hierarchical porous media for catalytic and separation processes

Trogadas, Panagiotis; Nigra, Michael M.; Coppens, Marc‐Olivier

doi:10.1039/c5nj03406j

Cited by 61 publications

(50 citation statements)

References 97 publications

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“…For instance, with the advances in nanotechnology it is now possible to engineer hierarchically structured nanocatalysts . Such catalytic nanostructures are normally composed of multiple nanoscale subunits, and they usually possess pore sizes of different length scales which is particularly important to catalysis . In addition, these advanced nanocatalysts have many outstanding characteristics, such as low density, high specific surface area, and large pore volume .…”

Section: Introductionmentioning

confidence: 99%

Architectural Designs and Synthetic Strategies of Advanced Nanocatalysts

Zhan

Zeng

2018

Advanced Materials

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Advanced nanocatalysts with high compositional and structural tailorability have emerged as a new class of heterogeneous catalysts exhibiting many new technical merits over their conventional counterparts. Generally, preparation of such catalysts involves the integration of catalyst components with compositional, size, and shape controls into a larger material system in order to bring along collective and synergetic effects of individual components. Herein, a brief review of architectural designs and synthetic strategies for making these nanocatalysts is presented. Due to length constraints, only four major types of them are highlighted together with some general rules of design and synthesis. Finally, a critical outline of future perspective in this field is proposed.

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Section: Introductionmentioning

confidence: 99%

Architectural Designs and Synthetic Strategies of Advanced Nanocatalysts

Zhan

Zeng

2018

Advanced Materials

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“…The wearer may suffer from heat stress and discomfort as the cloth prevents evaporation . To fabricate waterproof breathable membranes, researchers have already used several methods (i.e., biaxial stretching, template‐based methods, and phase separation) to establish interconnected porous structure . The available membranes in the market (e.g., Gore‐Tex, eVent) based on these technologies are quite expensive.…”

Section: Introductionmentioning

confidence: 99%

Electrospun waterproof breathable membrane with a high level of aerosol filtration

Maksoud

Lameh

Fayyad

et al. 2017

J of Applied Polymer Sci

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In this study, several nanofibrous polyurethane (PU) webs were electrospun (ES) by changing different effective parameters (e.g., polymeric concentration, voltage, feed flow, etc.). The physical-chemical properties of the webs (i.e., average fiber diameters, thickness, areal density, porosity, contact angle, waterproofness, air permeability (AP), water vapor transmittance, and aerosol filtration) were studied based on the standard test methods. A commercially available waterproof breathable (WPB) fabric was used as a reference for benchmarking. The beads-free webs with an average fiber diameter as small as 200 nm were achieved from electrospinning of 10 wt % PU in N,N-dimethylformamide, at feed rate of 0.5 mL/h, applied voltage of 25 kV, and tip-to-collector distance of 15 cm. By optimizing the electrospinning parameters, a web with a high level of waterproofness, high AP, and high water vapor transmission rate (WVTR) was obtained. In addition, the selected ES membrane showed very promising aerosol filtration efficiency with complete removal of particles larger than 0.5 mm, and 94% reduction in the concentration of smaller particles. We found a linear empirical equation for the estimation of AP and WVTR based on the average pore size diameter, the membrane thickness, and the porosity with very high regression coefficients (R 2 > 0.97).

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“…Here, a more systematic nature-inspired approach [21][22][23] is used to design (Fig. 1A) and evaluate against conventional serpentine flow-field based PEFCs, the performance of PEFCs with flow fields guided by the structure of a lung.…”

Section: Introductionmentioning

confidence: 99%

“…21,42 Larger, 3D printed fractal flow-fields (25 cm 2 surface area) with N = 4 are compared to conventional, serpentine flow-field based PEFCs. Performance results (Fig.…”

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confidence: 99%

A lung-inspired approach to scalable and robust fuel cell design

Trogadas

Cho

Neville

et al. 2018

Energy Environ. Sci.

147

179

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A lung-inspired approach is employed to overcome reactant homogeneity issues in polymer electrolyte fuel cells. The fractal geometry of the lung is used as the model to design flow-fields of different branching generations, resulting in uniform reactant distribution across the electrodes and minimum entropy production of the whole system. 3D printed, lung-inspired flow field based PEFCs with N = 4 generations outperform the conventional serpentine flow field designs at 50% and 75% RH, exhibiting a B20% and B30% increase in performance (at current densities higher than 0.8 A cm Broader contextFlow-field design is crucial to fuel cell performance, since non-uniform transport of species to and from the membrane-electrode assembly results in significant power losses. The long channels of conventional, serpentine flow fields cause large pressure drops between inlets and outlets, thus large parasitic energy losses and low fuel cell performance. This issue is exacerbated for small, portable fuel cells, where the power required for fluid transport should be minimal. To ensure uniform distribution of reactants across the electrode and a low pressure drop, we use a nature-inspired design that is rooted in thermodynamic and mechanical fundamentals, rather than biomimicry in a narrow sense. Inspiration is derived from the structure of the human lung, which ensures uniform gas distribution via an optimized fractal structure linking bronchi to alveoli, and realizing a remarkable combination of minimal entropy production, low pressure drop, and scale-invariant operation. Our 3D-printed, conducting flow-field plates maintain these unique characteristics of the lung, resulting in improved fuel cell performance over conventional serpentine flow-field based fuel cells. Uniformity in reactant distribution and minimal pressure drop are retained during scale-up, demonstrating the robustness of the proposed nature-inspired approach across length scales.

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Nature-inspired optimization of hierarchical porous media for catalytic and separation processes

Abstract: Nature-inspired structuring at the meso-scale: broad macropores separate the mesoporous catalyst grains.

Cited by 61 publications

References 97 publications

Architectural Designs and Synthetic Strategies of Advanced Nanocatalysts

Architectural Designs and Synthetic Strategies of Advanced Nanocatalysts

Electrospun waterproof breathable membrane with a high level of aerosol filtration

A lung-inspired approach to scalable and robust fuel cell design

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