This study reports the catalytic performance of 8Ni (8wt% Ni) and 6Ni2M (6wt% Ni, 2wt% M (M: Co, Cu, Rh)) anchored on BaZr0.4Ce0.4Y0.1Yb0.1O3-δ, an anode backbone material of proton-conducting ceramic...

Summary Dry reforming of methane assisted by 5 wt% Ni‐X alloy catalysts (X: Co, Cu, Pd, and Rh) anchored on γ‐alumina is evaluated for comparing the synergetic effect of alloys at once as catalysts for dry reforming of methane at low temperatures of 400°C‐600°C. Characterization of catalysts confirms alloy formation, structural properties, and adsorption properties that affect the performance of each bimetallic catalyst. Catalytic performance is evaluated from the perspective of initial activity, syngas production and selectivity, long‐term stability, as well as energy efficiency at powder level not previously addressed, followed by post‐analysis for carbon formation. The results show that Ni‐Rh/Al2O3 and Ni‐Co/Al2O3 are highly active and stable during the reaction. Ni‐Rh/Al2O3 shows higher CH4 and CO2 conversions at 550°C as 32.71% and 84.69% of those at equilibrium, respectively. Similarly, CH4 and CO2 conversions of Ni‐Co/Al2O3 at 550°C are 26.17% and 71.76% of those at equilibrium. They exhibit better long‐term stability than a Ni monometallic catalyst, decreasing the degradation rate by 60% for Ni‐Rh/Al2O3 and 40% for Ni‐Co/Al2O3. Such improvement is even more pronounced when the temperature decreases from 500°C to 400°C, implying their potential as catalysts for dry reforming of methane at low temperatures. However, for every performance indicator, Ni‐Pd/Al2O3 and Ni‐Cu/Al2O3 exhibit low performance. These tendencies are mainly attributed to the synergetic effect of alloy and apparent activation energies for reactions. Based on such experimental results, it is discussed that Ni‐Rh/Al2O3 and Ni‐Co/Al2O3 are feasible and promising catalysts for dry reforming of methane even at low temperatures.

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Direct methane PCFCs are promising electrochemical devices that address the technical and economic challenges associated with using pure hydrogen, such as the high cost of green production, transportation, and long-term storage. However, Ni, a conventional monometallic catalyst has sluggish reaction kinetics and a low tolerance for carbon cocking under CH4 operation, limiting its wider applications. Herein, we develop a self-assembled Ni-Rh bimetallic catalyst through Ni exsolution and Rh surface decoration in a fuel electrode. The Ni-Rh bimetallic catalyst shows remarkably high catalytic activity with an exceptional performance of ~ 0.50 W/cm2 at 500 ℃. Moreover, the catalyst significantly improves the stability with a degradation rate of 0.02%/h at 500 ℃; this value is ~ 20-fold lower than that of conventional PCFC (0.4%/h). Synchrotron-based in situ X-ray photoelectron spectroscopy reveals that the Ni-Rh bimetallic catalyst initiates a self-carbon cleaning process due to its high-water dissociation reaction, allowing sustainable operation.