Mn促进CuFe催化剂合成气制低碳醇的研究

Catalytic conversion of syngas to low-carbon alcohols over Mn-promoted CuFe catalysts

采用共沉淀法制备了一系列n(Cu)∶n(Fe)∶n(Mn)为1∶1∶(0, 0.25, 0.5, 1.0, 1.5)的Cu-Fe-Mn催化剂,在固定床反应器中考察其在相对温和条件下:260℃、3.0MPa、V(H_2)∶V(CO)=2∶1,体积空速GHSV=2400h^(-1),合成气制低碳醇的活性。通过比表面积测试(BET)、H_2-程序升温还原(H2-TPR)、X射线衍射(XRD)以及扫描电子显微镜(SEM)等揭示了催化剂性能与结构之间的关系。在260℃、3.0MPa反应条件下,考察了不同含量的锰对铜铁基催化剂合成低碳醇的影响,结果表明:催化剂CuFeMn_(1.0)表现出较佳的CO转化率50.5%,且低碳醇选择性由CuFe催化剂的6.8%提高至10.2%,由于锰的引入提高了Cu-Fe-Mn-O物相的形成,增加了CO吸附位点,促进了CO活化,从而促进了反应的进行和低碳醇的生成。

A series of Cu-Fe-Mn catalysts with the Cu:Fe:Mn molar ratios of 1∶1∶(0,0.25,0.5,1.0,1.5)were prepared by co-precipitation method.The catalytic performance of the catalysts on the synthesis of low-carbon alcohols from syngas was investigated in a fixed-bed reactor under relatively mild conditions:260℃,3.0MPa,V(H2)∶V(CO)=2∶1 and GHSV=2400h-1.The relationship between catalytic performance and structure was revealed by N2 physical adsorption(BET),X-ray diffraction(XRD),temperature-programmed reduction of hydrogen(H2-TPR),and scanning electron microscopy(SEM).The effect of Mn contents in the catalyst on the synthesis of low-carbon alcohols was investigated under the reaction conditions of 260°C and 3.0MPa.The experimental results showed that the catalyst CuFeMn1.0 exhibited a higher CO conversion of 50.5%,and its low-carbon alcohols selectivity increased from 6.8%of catalyst CuFe to 10.2%.Due to the introduction of Mn,the formation of Cu-Fe-Mn-O phases is improved,the adsorption sites of CO increase,and the CO activation is promoted,which promotes the reaction and the formation of low-carbon alcohols.