Citric acid-assisted synthesis of γ-alumina-supported high loading CoMo sulfide catalysts for the hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) reactions

摘要: In the present work, effect of citric acid (i.e., adsorption-assisting agent) and thermal treatment over acid-synthesized CoMo catalyst precursors were investigated. The catalysts prepared by wet co-impregnation γ-alumina extrude with acid-containing aqueous solution in medium (pH = 2–3) treated at various temperatures (typically between 110 400 °C) an air atmosphere. γ-alumina-supported sulfide evaluated using two different feeds (a model feedstock containing S N compounds (hereafter feed 1) a real 2). It was found that synthesis alumina-supported high loading precursor as chelating agent impregnation takes place mainly through uniform deposition–precipitation Co complex Mo citrate onto alumina. This process leads to formation nanodispersed species effectively mitigate β-CoMoO4 during temperature 350 °C). decomposition reaction aqueous-complex deposited on alumina started 220 °C. gradual degradation whole metal increasing decreased activity because apparent poorly reducible mixed-metal oxides precursor. use synthesize formulations enhances not only C–S bond scission direct desulfurization pathway, but also hydrogenation route.