Abstract:

Three catalysts with fixed compositions of MoO3, CoO, P2O5 of 13.50%, 2.11% and 4.16%, respectively were prepared by substep impregnation method with different P modification orders and characterized by XRD, H2-TPR, HRTEM techniques. The effect of phosphorus modification sequence on hydrodesulfurization performance of the catalysts was studied with the gasification tar distillates as raw materials. The results show that the P modification orders have different effect on acid sites distribution, reduction and sulfurization of active components as well as the pore structure of the catalysts, leading to a different HDS performance. The catalyst prepared by phosphoric acid pre-impregnation has the highest hydrodesulfurization activity；the sulfur removal rate reaches 96.98%.

Key words: phosphorus modification, coal tar, hydrodesulfurization, catalysts