CoMo/Al2O3 Hydrodesulfurization Catalyst Modified with Nitrilotriacetic Acid: Preparation Without Use of NH4+ and NO3− Ions.

Impregnation solutions for the preparation of NTA-modified CoMo/Al2O3 hydrodesulfurization catalysts were prepared without use of unnecessary and disrupting NH4+ and NO3− ions. The reaction-dissolution took place in the suspension of NTA, CoCO3·xH2O and MoO3 (here DISUSPEN method). The conventional solutions, prepared in the literature using NTA, NH4OH, MoO3 and Co(NO3)2, (here DISAMON method), were neutral or basic. The solid obtained by their drying was partly crystalline. The DISUSPEN solutions were acidic, with pH = 1.0–1.5. The DISUSPEN solids were XRD-amorphous with glass-like appearance. Much less nitrogen-containing emissions is produced during in-situ sulfidation of DISUSPEN catalysts as compared with DISAMON catalysts. Catalysts prepared by the DISUSPEN method are more active in HDS of thiophene than those prepared by the conventional DISAMON method. [ABSTRACT FROM AUTHOR]