Thesis (M.Eng.)--Chulalongkorn University, 2006

In the present study, differences in characteristics and catalytic activity towards CO hydrogenation of Co catalysts dipersed on various boron-modified MCM-41 supports were investigated. The various weight ratios of MCM-41/B were prepared by incipient wetness impregnation method, then calcined them in air. Then, consequently impregnated with the cobalt precursor. After calcinations, the various samples were characterized using N[subscript 2] physisorption, XRD, SEM/EDX, TEM, TPR and H[subscript 2] chemisorption CO hydrogenation (H[subscript 2]/CO = 10/1) was also performed to determine the overall activity and selectivity. It revealed that the size of Co oxide species depends on the boron content on modification support. A wide range of variables including particle size, support interaction, and the boron content can affect the kinetics of reduction. It was found that for the boron modified MCM-41 catalyst, the catalyst dispersed on the high boron content support exhibited low activities due to low reduciblilty. With small amount of cobalt loading, activity decreased due to a decrease in reducibility. Selectivity to C[subscript 2]-C[subscript 4] products slightly increased with increasing boron loading.