Abstract: CuO catalysts supported on SBA-15 were prepared by chelating Cu2+with γ-aminopropyltrimethoxysilane (APTS) on the SBA-15 support and were tested for selective hydrogenation of crotonaldehyde. The CuO/SBA-15 catalysts with different CuO loadings were characterized byX-raydiffraction, N2 sorption, and hydrogen temperature-programmed reduction (H2-TPR). N2 sorption results showed that the samples maintained a fine 2D-hexagonal structure after the CuO was loaded, whereas the BET surface area and pore volume decreased with increasing Cu content. H2-TPR results revealed that there were three Cu species: finely dispersed CuO, bulk CuO, and Cu2+ions incorporated into the framework of SBA-15. Catalytic activity of each species was evaluated. The finely dispersed CuO had the highest activity, and the bulk CuO had medium activity, while the Cu2+in the SBA-15 framework was inactive in the reaction. These indicated that the finely dispersed Cu species were the active phase for the reaction. Furthermore, the catalyst calcined under N2 instead of air could increase the content of the finely dispersed CuO, which could consequently enhance the catalytic activity.

Key words: copper oxide, SBA-15 molecular sieve, crotonaldehyde, hydrogenation, γ-aminopropyltrimethoxysilane