In response to energy shortages, the imperative to develop clean energy sources is paramount for fostering the sustainable advancement of contemporary society. Given the persisting challenges in hydrogen storage and transportation, solid oxide fuel cells (SOFCs) fueled by hydrocarbons have emerged as a focal point of scientific investigation. However, the performance degradation caused by carbon deposition, resulting from incomplete hydrocarbon oxidation on conventional nickel-based cermet anodes in SOFCs, significantly impairs its potential for widespread commercial viability. The Zr_0.1Ce_0.9O₂ catalyst has demonstrated outstanding anti-carbon deposition capability coupled with elevated oxide-ion conductivity. Nevertheless, the electrochemical performance of the ceramic electrode is subpar in comparison to that achieved with a Ni-cermet catalyst.

Herein, we report a carbon-resistant anode with Zr_0.1Ce_0.85X_0.05O_2-δ-SrFe_0.75Mo_0.25O_3-δ (X = Fe, Co, Ni, Cu) (ZDC_X-SFM) composite structure. ZDC_X nanoparticles were synthesized using the Sol-gel method. Notably, strained Fe, Co, Ni and Cu nanoparticles can be synthesized on the ZDC bulk through hydrogen annealing, with their surface morphology is modifiable by adjusting the doping concentration and annealing temperature. Significantly, compared to other samples, the introduction of Cu significantly enhanced grain growth. Characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy indicated alterations in lattice strain within the catalyst, accompanied by a concomitant rise in surface oxygen vacancy concentration during metal exsolution. The doping of ZDC with Fe, Ni, and Cu leads to a notable increase in its cubic lattice parameters, which escalate from 5.3876 Å to 5.3881 Å for Fe, 5.3889 Å for Ni, and 5.3887 Å for Cu. Only cobalt doping led to a slight reduction in lattice parameters, decreasing from 5.3876 Å to 5.3875 Å. Doping with different transition metals consistently resulted in an increased ratio of Ce³⁺.

After being mixed with SFM, the electronic conductivity of ZDC_X increased, rendering it suitable as an anode material. A single cell was fabricated with ZDC_X-SFM as the anode, La_0.8Sr_0.2Ga_0.8Mg_0.2O_3−δ (LSGM) as the electrolyte, and La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) as the cathode. Numerous electrochemical characterizations were performed to evaluate its performance. Electrochemical impedance spectroscopy analysis reveals a reduction in polarization resistance. Additionally, the primary reaction process and the rate-limiting step were further clarified through the analysis of relaxation time distribution. Overall, this study demonstrates a stable and active composite catalyst for energy applications.