A series of Cr-containing MCM-41 molecular sieves crystallized at room temperature with a hexagonal and well-ordered structure were synthesized. XRD, FT-IR and DRS UV-Vis techniques were used to characterize the samp.es. The results indicate incorporation of Cr into the MCM-41 framework, and dispersion of some Cr2O3 on the surface or/and in the bulk of the MCM-41. Test of catalytic properties of the series of samples for the topic reaction was carried out using a continuous-flow fixed-bed quartz reactor. Factors influencing the catalytic performance for this title reaction, such as Cr/Si ratio in MCM- 41 and reaction temperature were investigated. The experimental results indicate that over the 5%Cr- MCM-41 a 43.27% conversion of ethane and a 86.70% selectivity for ethylene were achieved in the ethane dehydrogenation with CO2 to ethylene at 973 K. It is suggested that both Cr6+ and Cr3+ are the catalytic activity center. A series of Cr-containing MCM-41 molecular sieves crystallized at room temperature with a hexagonal and well-ordered structure were synthesized. XRD, FT-IR and DRS UV-Vis techniques were used to characterize the samp.es. The results indicating incorporation of Cr into the MCM-41 framework, and dispersion of some Cr2O3 on the surface or / and in the bulk of the MCM-41. Test of catalytic properties of the series of samples for the topic reaction was carried out using a continuous-flow fixed-bed quartz reactor. Factors influencing the catalytic performance for this title reaction, such as Cr / Si ratio in MCM- 41 and reaction temperature were investigated. The experimental results that that over the 5% Cr- MCM-41 a 43.27% conversion of ethane and a 86.70% selectivity for ethylene were achieved in the ethane dehydrogenation with CO2 to ethylene at 973 K. It is suggested that both both Cr6 + and Cr3 + are the catalytic activity center.