Ce和Mn改性Co/AC催化合成气制低碳醇性能研究OA

Producing low-carbon alcohols(C2～C6 alcohols)from syngas have received extensive attention due to its excellent economic property.The Co-based catalyst is one of the main catalysts for producing low-carbon alcohols from syngas,but the Co-based catalyst currently has the problem of low selectivity for low-carbon alcohols.Using the co-precipitation method,Ce and Mn modified Co/AC catalysts(Ce-Co/AC and Mn-Co/AC with Co mass fraction of 15.0%and Ce or Mn mass fraction of 7.5%)were prepared,respectively.The structures of the catalysts were characterized by XRD,N2 adsorption/desorption and H2-TPR,and the catalytic performances of catalysts for producing low-carbon alcohols from syngas(calculating by the average values after 7 d of reaction)under the conditions of temperature of 250℃,pressure of 3.0 MPa and syngas(V(H2):V(CO)=2:1)flow rate of 75 mL/min were evaluated.The results show that compared with Co/AC,the introduction of the additives Ce and Mn both can improve the dispersion of Co species on the catalyst surface and reduce the crystal size of Co0 species.Among them,the content(mole fraction)of surface Co0 species in Mn-Co/AC is 66.0%.Under the experimental conditions,the CO conversion rate of Ce-Co/AC is 2.29%,and the total alcohol selectivity is 32.03%and m(low-carbon alcohols)/m(total alcohols)is 68.06%.Mn-Co/AC exhibits better catalytic performance with CO conversion rate of 3.99%,total alcohol selectivity of 33.23%and m(low-carbon alcohols)/m(total alcohols)of 79.36%.