关键词: 钒 , 咔唑 , 磷化钨 , 加氢脱氮 , 选择性

Abstract: γ- Al₂O₃ as a support , a series of tungsten phosphide catalyst s containing vanadium were prepared by the method of co - impregnation and temperature programmed reduction ( TPR) in H₂. The catalyst s were characterized by XRD, BET, TG, XPS. Carbazole hydrodenit rogenation ( HDN) activities of catalyst s were tested by a high pressure micro - reactor in condition of 3 MPa , 360 ℃and a space velocity of 4 h^{- 1}. The result show that dispersity of active species WP on the support surface is affected by adding some content of vanadium into tungsten phosphide catalyst. The cooperative effect is greatly between vanadium and support and active species with vanadium content of 5 %, which resulting in a very smaller changing in XRD pattern. Adding some content of vanadium during the preparation of catalyst produced the original phosphiding-reduction temperature of W species on the support surface for catalyst s precursor increasing and phosphiding - reduction extent decreasing, while the amount of high valence of W⁶⁺ on the surface of catalyst s are improved. Catalyst with vanadium content of 1 % is favor to carbazloe HDN reaction, which gaving 12. 7 % higher carbazole HDN conversion than that without vanadium. It is also observed that carbazole HDN reaction showed three paths: a very low direct denit rogenation selectivity (only 3. 2 %, the first path way ) and a high hydrodenit rogenation selectivity ( hydrogenation to saturating one benzene rings followed by denit rogenation, the second path way, and hydrogenation to saturating two benzene rings followed by denit rogenation, the third path way) . The third path way is a primary rout and the HDN selectivity reached 91. 0 %. Compared to the tungsten phosphide catalyst without vanadium , carbazole HDN selectivity of catalyst with 1 % content of vanadium showed a slightly decreased by the first path and gave a 6. 7 % lower by the third path, 7. 3 % higher by the second path.

Key words: Vanadium , Carbazole , Tungsten phosphide , Hydrodenit rogenation , Selectivity