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Liu, Mingfei

Publications and source records attributed to Liu, Mingfei.

16 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Electrostatic Force Microscopic Characterization of Early Stage Carbon Deposition on Nickel Anodes in Solid Oxide Fuel Cells

Carbon deposition on nickel anodes degrades the performance of solid oxide fuel cells that utilize hydrocarbon fuels. Nickel anodes with BaO nanoclusters deposited on the surface exhibit improved performance by delaying carbon deposition (i.e., coking). Here, the goal of this research was to visualize early stage deposition of carbon on nickel surface and to identify the role BaO nanoclusters play in coking resistance. Electrostatic force microscopy was employed to spatially map carbon deposition on nickel foils patterned with BaO nanoclusters. Image analysis reveals that upon propane exposure initial carbon deposition occurs on the Ni surface at a distance from the BaO features. With continued exposure, carbon deposits penetrate into the BaO-modified regions. After extended exposure, carbon accumulates on and covers BaO. The morphology and spatial distribution of deposited carbon was found to be sensitive to experimental conditions.

25 ENERGY STORAGE↗
DOE OSTI2015

An operando surface enhanced Raman spectroscopy (SERS) study of carbon deposition on SOFC anodes

Thermally robust and chemically inert Ag@SiO 2 nanoprobes are employed to provide the surface enhanced Raman scattering (SERS) effect for an in situ/operando study of the early stage of carbon deposition on nickel-based solid oxide fuel cell (SOFC) anodes. The enhanced sensitivity to carbon enables the detection of different stages of coking, offering insights into intrinsic coking tolerance of material surfaces. Application of a thin coating of gadolinium doped ceria (GDC) enhances the resistance to coking of nickel surfaces. The electrochemically active Ni–YSZ interface appears to be more active for hydrocarbon reforming, resulting in the accumulation of different hydrocarbon molecules, which can be readily removed upon the application of an anodic current. Operando SERS is a powerful tool for the mechanistic study of coking in SOFC systems. It is also applicable to the study of other catalytic and electrochemical processes in a wide range of conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Solid oxide fuel cells having porous cathodes infiltrated with oxygen-reducing catalysts

Solid-oxide fuel cells include an electrolyte and an anode electrically coupled to a first surface of the electrolyte. A cathode is provided, which is electrically coupled to a second surface of the electrolyte. The cathode includes a porous backbone having a porosity in a range from about 20% to about 70%. The porous backbone contains a mixed ionic-electronic conductor (MIEC) of a first material infiltrated with an oxygen-reducing catalyst of a second material different from the first material.

25 ENERGY STORAGE↗
DOE OSTI2013

High-performance Ni–BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb) membranes for hydrogen separation

Cermet membranes composited of Ni and doped barium cerate have been widely studied for hydrogen separation; however, their practical application is limited primarily by the relatively low permeation rate and instability of doped barium cerate in H 2 O and CO 2 containing gases. Here we report our findings on the development of a thin-film cermet membrane consisting of Ni and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb), supported on a porous Ni–BZCYYb substrate. High fluxes of 1.12 and 0.49 ml min -1 cm -2 have been demonstrated at 900 °C and 700 °C, respectively, when hydrogen was used as the feed gas on one side and N2 as the sweep gas on the other side. Most importantly, the high-performance membrane can be easily fabricated by a cost-effective particle-suspension coating/co-firing process, offering great promise for large scale hydrogen separation applications.

08 HYDROGEN↗