Solid oxide fuel cells fed with dry ethanol: The effect of a perovskite protective anodic layer containing dispersed Ni-alloy @ FeOx core-shell nanoparticles

Ethanol internal reforming in solid oxide fuel cells: A path toward high performance metal-supported cells for vehicular applications

“…Since MS-SOFCs have a highly porous structure [11,64] the concentration polarization across the thickness of the anode is expected to be negligible and have none or minimal impact on the cell ASR. This is often not the case for thick and dense anode supported cells (ASCs) which show severe mass transport limitation [1,48,50] for ethanol (although not observed in hydrogen fuel). The ASR at high current (low voltage) is further increased by mass transport restriction arising from resistance to diffusion in the anode due to anode layer thickness, density or tortuosity.…”

“…To improve internal reforming of ethanol fuel in conventional SOFCs, the primary approach has been to augment or replace the Ni anode electrocatalyst. The most notable catalyst compositions can be classified into four categories: (1) Ni-based anodes such as Ni-YSZ [20,40,41], Ni-GDC [42,43], Ni-CeO2 [44,45], Ni-CZO [46], Ni-BZCYYb [47], Ni-BZCY [22,47], Ni-Al2O3 [22], Ni-SrFeLaCoO3 [48], (2) Ni-free anodes including Cu-CGO [1,41,49], Cu-CeO2 [50,51], Cu-CZO [37], Cu-CeO2-ScSZ [35,52], Ir-CGO [44], Ru-CGO [1], Ru-Cu-CZO [1], Cu-Co(Ru)-CZO [53], Pd-LSCM [54], Ru-LSCM [55], (3) Ni-alloys with Sn [56], Fe [36,48], Co [48,57], and (4) Ni-free alloys such as CuZnAl [58], and CuCoRu [53]. The majority of these studies reported low performance with ethanol (peak power <0.3 W cm -2 at 600-800 ºC), due to the use of inherently low-performing cells, incomplete reforming, or both.…”

“…Virkar et al [20] achieved 0.3 W cm -2 at 600 ºC and 0.8 W cm -2 at 800 ºC with Ni-YSZ anode. Arico et al [48] obtained 0.6 W cm -2 at 800 ºC with Fe, Ni-alloy core-shell reforming catalyst. It is worth noting that Ni remains a major catalyst component for internal reforming of ethanol fuel.…”

“…Many literature reports on conventional SOFCs (in particular, anode-supported) also show severe mass transport limitation for ethanol, observed as a limiting current density that is not seen when operated in hydrogen fuel [1,48,50]. Presumably, this is due to hydrogen concentration polarization arising from the density and thickness of the anode support and low hydrogen concentration in the reformed fuel.…”

A strategy to reduce the impact of tar on a Ni ‐ YSZ anode of solid oxide fuel cells

“…A solid oxide fuel cell (SOFC) is a clean power generation system that has a high efficiency because it directly converts the chemical energy of fuels into electricity. Fuel flexibility is an important advantage of SOFC, and theoretically, any substance that can be oxidized, such as solid carbon, ammonia, carbon monoxide, ethanol, or other hydrocarbons, can be used as a fuel in an SOFC. A high‐temperature SOFC (HT‐SOFC; higher than 800°C) can directly generate electricity using a high‐temperature raw COG after the initial dust removal.…”