Effects of Pyrolyzing and Phosphiding on Dibenzothiophene Hydrodesulfurization of MOF-Derived Ni₂P

To investigate the potential utilization of MOF templates in hydrodesulfurization (HDS) of large sulfur-containing compounds, MOF-derived Ni₂P was prepared and characterized by XRD, TG, SEM, TEM, XPS and Raman. The findings indicate that MOF-derived Ni₂P catalyst exhibits significantly enhanced Hydrodesulfurization (HDS) activity compared to conventional unsupported Ni₂P. A modified pyrolysis and phosphiding condition allowed the stacking of central Ni atoms to be aggregated loosely, and morphology of MOF-derived Ni₂P can be controllably transmitted from polyhedral to petal-like. A lower pyrolysis temperature tends to reduce density of Ni aggregates and cluster size of Ni₂P(111), thereby facilitating the phosphiding of Ni aggregates and enhancing the catalytic activity of MOF-derived Ni₂P in HDS process. Increasing the duration time of pyrolysis at lower temperatures does not accelerate the aggregation of particles, but makes petals on surface of MOF-derived Ni become thinner and eventually disappear, until coral-like nanosphere aggregates with uniform size are formed. The gradually elimination of MOF framework renders nickel aggregates more susceptible to phosphiding. The collapse of pore structure of MOF template can impact HDS activity of MOF-derived Ni₂P. Prolonging pyrolysis time causes the spacing between Ni₂P clusters to diminish, thereby significantly decreasing reactivity of Ni₂P-400-4-275 compared to Ni₂P-400-2-275 in DBT–HDS.