Impact of Nickel Phosphides Over Ni/SiO2 Catalysts in Dry Methane Reforming

A series of relative inert SiO2 supported NiP-x/SiO2 catalysts, containing different ratio of metallic nickel to nickel phosphides, were employed to clarify the synergistic effect of metallic nickel-nickel phosphides in dry methane reforming reaction. Ni/SiO2 catalyst exhibits good activity but severe carbon deposition and visible nickel particles sintering in dry methane reforming, which results in evident deactivation after 50 h reaction. The presence of P increases the dispersion of nickel species, results in smaller nickel species particles size. The co-existence of metallic nickel and nickel phosphides species was confirmed by multiple characterizations. Because of the relative stronger CO2 dissociation properties, NiP-x/SiO2 catalysts exhibit higher resistance of carbon deposition. In addition, P content makes great difference to not only carbon deposition but also activity in dry methane reforming. NiP-3/SiO2, which has good activity, stability and anti-coking properties in dry methane reforming, is the optimal catalyst in our study scope. [GRAPHICS] .

Automated summary

This study investigates the synergistic effect of metallic nickel and nickel phosphides in dry methane reforming reaction. The addition of phosphorus improves the dispersion of nickel species and enhances the resistance to carbon deposition. NiP-3/SiO2 catalyst exhibits the best activity, stability, and anti-coking properties.