Highly efficient epoxidation of styrene and α-pinene with air over Co2+-exchanged ZSM-5 and Beta zeolites

Synthesis and catalytic application of SAPO-5 by dry-gel conversion for the epoxidation of styrene with air

“…Very recently, our group has reported the efficiencies of simple ion-exchanged Co-ZSM-5 and Co-Beta [38], Co-SAPO-34 [28], Co-5A and Co-MOR [39] for dissociating triplet ground state of O 2 to epoxidize singlet olefins with a high conversion and selectivity. It is noteworthy that the above-stated zeolites or molecular sieves were hydrothermally synthesized with organic quaternary ammonium ions or amines as structure-directing agents.…”

Co2+-exchanged SAPO-5 and SAPO-34 as efficient heterogeneous catalysts for aerobic epoxidation of alkenes

“…However, whether DMF is a reductant or not has been considered as a controversial topic [17,30,33]. Actually, DMF could not be recognized as a real reductant in our catalytic system, different from the case reported in the literature [33].…”

“…1). Furthermore, control experiments were carried out according to the method described in the literature [17]. As shown in Fig.…”

“…Among these oxygen donors, molecular oxygen is the most desired oxidant with respect to the economic consideration. This requires a scrutiny of potential catalysts that can efficiently catalyze the epoxidation reactions, for triplet ground state of O 2 disfavors reactions with singlet organic compounds [11][12][13][14][15][16][17].…”

“…Typically, the selective oxidation of alkenes with oxygen/air have achieved encouraging results over Co 2+ -exchanged faujasite-type zeolites [11], Co-X [12,14], Co-Y [15], Co-SBA-15 [16], Co-ZSM-5, and Co-Beta [17]. During the last decade, silico-aluminophosphate molecular sieve SAPO, have attracted much attention because of their excellent catalytic performance for a series of reactions, e.g.…”