【摘要】 以MoO₃-SiO₂为主催化剂,研究了助剂Fe、Co的催化作用。Fe的加入,提高了催化剂对甲烷的脱氢能力,从而提高生成HCHO的选择性;Co的掺入与Mo形成CoMoO₄相,改善了MoO₃在含水气氛中的稳定性。考察了空气作氧化剂取代N₂O进行CH₄选择氧化的可能性。反应过程中水的加入抑制了深度氧化反应的进行,使生成HCHO选择性提高。更多还原

【Abstract】 The effects of promoters iron and cobalt, the possibility of substitution of air for N_O as oxidizing agent and the influence of water on the reaction were investsgated. The TPD results showed that the addition of iron enhances the dehydrogenation ability and increased the selectivity of HCHO. The LRS results showed that the introduction of cobalt results in the formation of "CoMoO₄" phase and increases the stability of MoO₃ in the presence of water. The comparative studies, using N₂O and air as oxidizing agent, indicated that over Mo-Fe-Co-O/SiO₂ catalyst at 500℃, CH₄:N₂O:N₂:H₂O= 1:3:1:4（mol）, the yield of HCHO is 3.4% and that at 400 ℃, CH₄: N₂:air:H₂O = 11: 8.4 : 3.3: 44, the yield of HCHO is 2.7%. However, when the catalyst is Mo-Fe-O/SiO₂, under otherwise equal conditions, the yield of HCHO is 4.6% and 2.6% respectively for N₂O and air. It was found that the addition of water increases the selectivity of HCHO.更多还原