Effect of Lanthanum Doping on the reactivity of unsupported CoMoS2 catalysts

Abstract

In the present study, catalytic systems based on La-doping were developed to improve the activity and performance of CoMoS2 hydrodesulfurization catalysts. Lanthanum-doped at 5, 10, or 25% of the Co content in CoMoS2 hydrodesulfurization catalysts were synthesized through a solvothermal process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses confirmed the catalysts were triphasic consisting of Co9S8, MoS2, and La2S3. The La doped catalysts showed enhanced catalytic activity compared with CoMoS2 synthesized under the same conditions. The CoMoS2 prepared under solvothermal synthesis conditions showed a catalytic activity of 6.80 mol g-1 s-1, however, the La0.05Co0.95MoS2 doping showed a catalytic activity of 6.51 mol g -1 s-1 whereas the La0.1Co0.9MoS2 and La0.25Co0.75MoS2 samples showed catalytic activities of 10.7 mol g-1 s-1. The reaction products indicated the major reaction pathway was direct desulfurization. The La0.25Co0.75MoS2 catalyst after one reaction cycle showed a lower amount of carbon, than the undoped CoMoS2 catalyst

    Similar works