Charaterization And Pyridine Hydrodenitrogenation Performance Of Molybdenum Carbide

鈽匨olybdenum carbide catalysts were prepared by temperature programmed reaction using CH₄/H₂ gas mixture to carburize molybdenum trioxide and characterized by XRD銆丅ET銆丼EM銆乆 PS techniques.TG-DTA in-situ was used to investigate the sy-nthesis mechanism of molybdenumcarbide catalysts.The hydrod-enitrogenation(HDN) performance of the catalysts were evaluated by usi-ng of pyridine as model reactants. The results were as follows:鈽匨oO₃ could be carburized intoå°¾-Mo₂C in CH₄/H₂ through the pat-hway:MoO₃鈫扢oO₂鈫扢oO_xC_y鈫扢o₂C and the proper carburizing temp-erature is about 675鈩?There are two species on the surface of Mo₂C,in-clude Mo²⁺ species and Mo^未+(5鈮の磣+鈮?) species.The promoters Ni and Co could change the process of carburization and decrease the carburiz-ing temperature of Mo₂C and increas the surface area of Mo₂C andchange the ratio of Mo/C and Mo/O on the surface of the Mo₂C cata-lysts. For the supported Mo₂C catalyst, Ni could reduce it's initial andterminal carburizing temperature, while Co merely increase the initial temperature,but couldn't effect the terminal carburizing temperature.Ni or Co could decrease the surface area of the supported Mo₂C catalyst,but had a little effection on the pore size distribution of the catalysts.鈽匨o₂C had a higher activity of pyridine HDN than MoS₂ and MoO₃．The optimal preparation conditions for Mo₂C were that the carburizing temperature was about 675鈩?carburizing space veloci-ty was about 1．8脳10⁴h^-1 , The suitable HDN conditions were that thereaction pressure was 4．0Mpa, and reactive space velocity is 2．5h^-1 .Ni-Mo₂C with Ni/Mo ratio of 0．3 and Co-Mo₂C with Co/Mo ra-tio of 0．4 had a higher pyridine HDN activity Ni-Mo₂C/纬-A l₂O₃ with Ni/Mo ratio of 0．4 and Co-Mo₂C/纬-Al₂O₃ with Co /Mo ratio of 0．4 and P-Mo₂C/纬-Al₂O₃ with P/Mo ratio of 0．1 had higher pyridine HDN activitives.