Co-Cu／SiO2催化剂的表征

Characterization of Co-Cu/SiO_2 Catalysts

用溶胶-凝胶法制备了Co-Cu/SiO2系列的担载型催化剂,采用SBET、TPR、XRD、O2滴定等技术对该催化剂进行了研究,并考察了催化剂在F-T合成反应中的催化性能.结果表明,样品的SBET较大,Co和Cu组分均很好分散;Cu2+的加入使得Co更易于被氢气还原,Co是经由Co3+→Co2+→Co0的还原过程,Cu的还原为Cu2+→Cu0;Cu2+的引入使得样品中钴的还原度增大,对F-T合成的催化性能有了一定的改善.

In this study, the catalysts of Co-Cu/SiO2 series were prepared by sol-gel method, and were characterized by the techniques of TPR, XRD, the titration of O2 and the measurement of the specific area of BET （ SBET）. Their catalytic performance for F-T synthesis was also investigated. The experimental results showed that the dispersion of the components of cobalt and copper supported on SiO2 were all well. The results of O2titration indicated that due to the existence of Cu^2＋ in the samples of Co-Cu/SiO2 the reduction of cobalt species was proceeded easily. TPR results revealed that only cobalt species was reduced via Co^3＋→Co^2＋→Co^0 process, while for Co-Cu/SiO2 catalysts, in addition to the reduction of cobalt species, the reduction from Cu^2＋ to Cu^0 was also observed. The improvement in the reducibility of catalyst and the cobalt dispersion contributed a little to the activity of the promoted catalysts for F-T synthesis.