Epoxidation of Propene by High-Throughput Screening Method Over Combinatorially Prepared Cu Catalysts Supported on High and Low Surface Area Silica

• Published in: Catalysis letters 2012-10, Vol.142 (10), p.1234-1243
• Main Authors: Duzenli, Derya, Seker, Erol, Senkan, Selim, Onal, Isik
• Format: Article
• Language: English
• Subjects: Activation energy; Catalysis; Catalysts; Chemical properties; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Combinatorial analysis; Epoxidation; Exact sciences and technology; General and physical chemistry; Industrial Chemistry/Chemical Engineering; Metal catalysts; Methods; Organic chemistry; Organometallic Chemistry; Oxygen; Physical Chemistry; Propylene; Rankings; Selectivity; Silica; Silicon dioxide; Sol-gel processes; Surface area; Test equipment; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Vapor phases
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-012-0867-4

Gas phase epoxidation of propene using molecular oxygen was studied by use of a high-throughput testing technique. A large number of catalysts including promoted and un-promoted Cu were synthesized in a much faster combinatorial fashion using a sol–gel method. Metal catalysts supported on high and low surface area silica were tested and ranked in a high-throughput activity and selectivity testing apparatus at different experimental conditions such as reaction temperature and reactant gas ratio. The amount of Cu loading and the addition of alkali promoters such as K and Li resulted in different tendencies in consumption rate for both silica materials. The maximum PO production rate was obtained as 25.82 μmol/g/cat./min (2.90 % conv. and 20.49 % selectivity) for 3 % Cu–2.25 % K catalyst supported on high surface area silica. There was no noticeable difference in structural and chemical properties of catalysts after modification with K when examined by XRD and TEM; however, the overall activation energy of un-modified catalysts (92 kJ/mol) decreased to 71 kJ/mol for K-modified catalyst. There was negligible difference between the activation energies calculated for PO production (75 vs. 77 kJ/mol). Graphical Abstract