A steel slag–derived Boudouard reaction catalyst for improved performance of direct carbon solid oxide fuel cells

Abstract

Summary Solid oxide fuel cells (SOFCs) can directly utilize solid carbon as fuel by integrating with the reverse Boudouard reaction in the anode chamber. Efficiency of the Boudouard gasification of solid carbon fuel is one of the crucial factors influencing the performance of direct carbon SOFCs (DC‐SOFCs). In this paper, a novel Boudouard reaction catalyst derived from steel slag was first introduced into DC‐SOFCs for improving the electrochemical performance. The catalytic activity of the steel slag was activated using the molten alkali method to decompose the inert mineral phases of the raw material. The steel slag–derived catalyst was loaded on the activated charcoal by a wet ball milling method. This kind of catalyst can match up to the readily available solid carbon fuels in cost. Promoted by this highly active Boudouard reaction catalyst, the initial Boudouard gasification temperature of the carbon fuel decreased by 99°C, and the producing rate of carbon monoxide doubled. Furthermore, the power outputs of the fuel cells increased from 91 to 159 mW cm−2, and the fuel utilization increased from 17.10% to 46.43% at 825°C. This study demonstrates that the steel slag–derived catalyst is a promising material for the performance improvement of DC‐SOFCs and may make a valuable contribution to their commercial application.

Solid oxide fuel cell using agroforestry waste as fuel: A balance between power output and fuel utilization

“…Our previous study revealed that the SS catalyst with active components of CaO and Fe 2 O 3 have catalytic activity on biomass pyrolysis, reforming reactions, and the Boudouard reaction (Table 3). 40 Promoted by the catalyst, biomass can produce more small molecule gas (CO, H 2 ), which will reduce the anode concentration polarization and significantly improve the output performance of the cell. Wang et al reported that when the cell configuration, anode materials and test conditions are identical, the anode concentration polarization is the main factor affecting the PPD, and the concentration polarization is determined by the concentrations of anode combustible gases 28 …”

“…The yield of the ATB char was 28%. In order to increase the gasification rate of the ATB sample, a mechanical mixing method was used to load the steel slag (SS)‐based catalyst of 50 wt% onto the ATB sample (ATB + SS) 40 . To prepare the ATB + SS sample, the catalyst was sieved through a 200 meshes sieve and then mixed with ATB powder in the mass ratio and ground in a mortar for 15 min.…”

“…In order to increase the gasification rate of the ATB sample, a mechanical mixing method was used to load the steel slag (SS)-based catalyst of 50 wt% onto the ATB sample (ATB + SS). 40 To prepare the ATB + SS sample, the catalyst was sieved through a 200 meshes sieve and then mixed with ATB powder in the mass ratio and ground in a mortar for 15 min. According to the same procedure, another group of samples, the medium density fiberboard (MDF) powder, the MDF char, and the MDF + SS, were prepared.…”

Repurposing Mining and Metallurgical Waste as Electroactive Materials for Advanced Energy Applications: Advances and Perspectives

“…As such, designing cost-effective catalysts for the Boudouard reaction is highly urgent. Recently, strontium slag [32,83] and steel slag [87] have been used for constructing Boudouard reaction catalysts. In Han et al's study, the application of strontium slag-derived catalysts can improve the DC-SOFC output from 189 to 248 mW•cm −2 at 850 • C, and the improved system attains a fuel utilization of 25.6% [83].…”

Plasma assisted CO2 splitting to carbon and oxygen: A concept review analysis

“…The catalyst must be pretreated with acetic acid, and without this pretreatment, carbon deposition results much more limited. This appears a limitation for a continuous process, but there are many alternative catalysts active in the Boudouard reaction, which were not explored by Luc et al [42] limiting their analysis to Fe and Fe2O3, and to 500°C as operational temperature, using as model for the study the direct carbon solid oxide fuel cells, but which typically operate at higher temperatures [48][49][50]. Note that the Boudouard reaction can be significantly promoted using microwaves [31].…”