Effect of SiO₂ amount on heterogeneous base catalysis of SiO₂@Mg-Al layered double hydroxide.

ABSTRACT: The effects of SiO₂ amount on the base catalysis of highly active finely crystallized Mg-Al type layered double hydroxides prepared by the co-precipitation method with coexistence of SiO₂ spheres, denoted as SiO₂@LDHs, were investigated. With the Si/(Mg + Al) atomic ratios of 0-0.50, the highest activity for the Knoevenagel condensation was observed in the case of Si/(Mg + Al) = 0.17, as the reaction rate of 171.1 mmol g(cat)^-1 h^-1. The base activity increased concomitantly with decreasing LDH crystallite size up to Si/(Mg + Al) atomic ratio of 0.17. However, above the Si/(Mg + Al) atomic ratio of 0.17, the reaction rate and TOF_base were decreased although the total base amount was increased. Results of TEM-EDS and ^29</

SUBMITTER: Shirotori M 

PROVIDER: S-EPMC9083954 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature