阶跃过渡应答技术研究Mo-V/Al_2O_3催化剂上乙烷氧化脱氢制乙烯反应的暂态动力学 Ⅰ.C_2H_6,O_2,C_2H_4和CO_2在催化剂上的吸附行为

STUDY OF TRANSIENT KINETICS OF OXYDEHYDROGENATION OF ETHANE TO ETHYLENE OVER Mo-V/Al_2O_3 BY STEP TRANSIENT RESPONSE TECHNIQUE Ⅰ.ADSORPTION BEHAVIOR OF C_2H_6,O_2,C_2H_4 AND CO_2 ON CATALYST SURFACE

用阶跃过渡应答技术研究了乙烷氧化脱氢反应的反应物C_2H_6,O_2,产物C_2H_4和主要副产物CO_2在MoO_3-V_2O_5/Al_2O_3催化剂上的吸附行为。结果表明:C_2H_6和C_2H_4在该催化剂上不吸附;氧为慢吸附、不可逆吸附;CO_2为可逆吸附,吸附量较小。并发现在无氧的条件下,乙烷能与催化剂表面上的晶格氧反应生成乙烯。这些结果对乙烷氧化脱氢反应机理的探讨有重要意义。

The adsorption behavior of C2H6,O2,C2H4 and CO2 on the surface of MoO3-V2O5//Al2O3 catalyst has been studied by the technique of step transient response(S-TR). The experimental results show that ( 1 ) C2H6 and C2H4 are not adsorbed on the surface of the catalyst;(2)O2 is adsorbed slowly and irreversiblely;(3) the by-product CO2 of ethane oxydehydrogenation is a reversible adsorption species and the adsorption amount is small;(4) in the absence of gaseous oxygen, the ethane can react with the surface lattice oxygen of the catalyst to yield ethylene. These results are important to the examination of the mechanism of the oxydehydrogenation of ethane to ethylene.