Catalytic combustion of hydrogen over La1−xSrxCoO3−δ + Co3O4 and LaMn1−xCuxO3+δ under simulated MCFC anode off-gas conditions

The activities of two perovskite catalysts, LaMn1−xCuxO3+δ (0 ≤ x ≤ 1) and La1−xSrxCoO3−δ (0 ≤ x ≤ 1), were tested for the catalytic combustion of hydrogen under simulated molten carbonate fuel cell (MCFC) anode off-gas conditions. The catalysts were prepared using the sol–gel citrate (SGC) method and were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, oxygen temperature-programmed desorption (O2-TPD), and temperature-programmed reduction (TPR) in order to discriminate the major properties governing the activities of the catalysts. The activity of LaMn1−xCuxO3+δ was the highest at x = 0.4, at which the reducibility of B-site cations and mobility of active oxygen were the most prominent. The activity of La1−xSrxCoO3−δ was strongly related to the amount of oxygen vacancies, and the by-produced Co3O4 had a positive effect, which was the reason why the catalyst at x = 0.6 (a mixture of La1−xSrxCoO3−δ + Co3O4) was comparatively active to those at x = 0.2 and 0.4.

Graphical abstractThe most active catalyst for the catalytic combustion of hydrogen in a simulated MCFC anode off-gas was LaMn0.6Cu0.4O3+δ, which was the most prominent in both the reducibility of B-site ions and the oxygen mobility.Figure optionsDownload full-size imageDownload high-quality image (158 K)Download as PowerPoint slideHighlights► LaMn1−xCuxO3 and La1−xSrxCoO3 were compared in combustion of MCFC anode off-gas. ► Among the tested catalysts, the most active catalyst was LaMn0.6Cu0.4O3. ► B-site ion reducibility and oxygen mobility affected the activity of LaMn1−xCuxO3. ► For La1−xSrxCoO3−δ, the co-produced Co3O4 generated synergy effects in activity.