A novel Ni phosphide-modified Ni/CeO 2 catalyst for dry reforming of methane

A novel Ni phosphide-modified Ni/CeO2 catalyst was developed for dry reforming of methane (DRM) and systematically characterized using BET, TEM-EDS, XPS, H2-TPR and TGA. The NiP-Ni/CeO2 catalyst demonstrated superior catalytic activity to the Ni/CeO2 catalyst at 750 °C over a 16-h test, with CH4 conversion of 75% vs. 44%, CO2 conversion of 77% vs. 49%, and an H2/CO ratio of 0.77 vs. 0.60. This enhancement was attributable to its increased surface area, improved Ni dispersion, and strengthened Ni-CeO2 interaction. However, although the NiP-Ni/CeO2 catalyst exhibited higher CH4 and CO2 dissociation rates (RCH4 and RCO2) than the Ni/CeO2 catalyst, the imbalance between them led to more severe carbon deposition. This was evidenced at 750 °C by a significantly higher RCH4/RCO2 ratio of 1.39 for NiP-Ni/CeO2, compared to 0.83 for the Ni/CeO2 catalyst. Therefore, optimizing the NiP-Ni/CeO2 catalyst to achieve a balanced RCH4 and RCO2 while maintaining high reaction rates remains a critical challenge for future research.