Gold nanoparticles supported on magnetic Metal Organic Framework: kinetics and mechanism of alkenes oxidation by dioxygen

Gold nanoparticles deposited on cubic metal organic framework (MOF) surface by homogeneous deposition precipitation method. For characterization of nanocatalysts several methods applied. XRD, SEM, TEM and TGA used for determination of morphology, texture properties, specific surface area and thermal stability. Au@MOF composites demonstrated high stability and six-time reusability was observed. TEM images showed that gold nanoparticles have proper dispersity on support surface. Metal organic framework provided high surface area for deposition of gold particles homogenously. The catalysts demonstrated high catalytic activity in aerobic oxidation of alkenes by oxygen under mild condition. Alkene oxides are the main product with more than 92% selectivity. The origin of catalytic activity of gold is not completely understood, but we think that the mail reason is interaction between the gold and support. Langmuir Hinshelwood mechanism is preferred according to concentration monitoring and kinetics investigation. Molecular oxygen adsorbed on surface radically and each oxygen radical play an effective role epoxide production.