Methane reforming based on solid oxide fuel cell (SOFC) is an effective way to realize clean utilization of fossil energy. The direct internal reforming of CH₄ is a process of converting methane into more chemically active syngas (i.e., H₂ and CO) by SOFC, and then further oxidizing into water and carbon dioxide to produce electricity. The application of CH₄ reforming based on SOFC shows some potential advantages. For instance, the internal reforming of CH₄ on the SOFC anode is an exothermic reaction, which can directly use the heat generated inside and reduce the continuous supply of external energy. And the chemical energy in the fuel is directly converted into electrical energy without going through multiple energy conversion stages, greatly improving the power generation efficiency. The products of SOFC are only H₂O and CO₂, and the water vapor in the tail gas can be condensed to capture high-purity CO₂, achieving zero carbon emissions. In addition, the high-temperature water vapor can also be used for waste heat utilization to achieve multi-level utilization of energy.

However, there is a carbon deposit problem in the case of SOFC using hydrocarbons as a fuel. When hydrocarbon is not fully converted into syngas upstream of SOFC, the fuel is directly introduced into the anode, where the carbon-containing gas is adsorbed, activated and dissociated to form carbon species. Also, O or OH adsorbed on the surface is insufficient, the carbon species diffuses into the catalyst, gradually accumulating and forming carbon deposits. Therefore, the anode pore and the transmission of the anode raw gas and product gas could be blocked, resulting in the failure of SOFC. The severity of which depends on the operating conditions (i.e., temperature, fuel composition and the catalytic performance of the anode material). The existing methods proposed in the literature mainly include that increasing the polarization current to promote the carbon elimination reaction, modifying other metals into the Ni-based anode to form an alloy anode, and adding a catalyst layer on the external surface of the anode. Among them, the addition of catalytic reforming layer on the outer surface of the anode is a recent research hotspot to inhibit carbon deposition. In order to ensure that the added catalyst layer can play an effective role in reforming hydrocarbons, we need to find a suitable catalytic coating to improve the catalyst activity of the reforming reaction. The type of CH₄ reforming reaction depends on the added fuel additives, which can be H₂O, O₂, and CO₂, corresponding to dry reforming of methane, wet reforming of methane and partial oxidative reforming, respectively.

Besides, carbon deposition on SOFC can be suppressed by optimizing the anode material. Four typical carbon resistant anode materials are summarized. Doped precious metals form bimetallic alloys on Ni-based catalysts, which produce synergistic effect and form small and highly dispersed metal particles, inhibiting the growth of Ni particles and carbon deposition. CeO₂-modified Ni-based anodes can promote oxygen mobility and capture massive active oxygen ions to enhance the flow of charge and accelerate the removal of carbon deposited on Ni surface. The Ni-based anodes modified with Ba oxides exhibit excellent WSC and have a high CO₂ adsorption capacity, promoting carbon removal. Ni-free anode materials are considered as alternatives to Ni due to their excellent electrical conductivity and low activity in catalyzing C-C bond formation. However, their limited catalytic activity restricts their commercial application.