Related Experiment Video
Updated: May 8, 2026

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation
Published on: July 18, 2017
Mechanistic investigation of nitridation-promoted reactivity and selectivity for propylene epoxidation in TS-1
Qiaoyun Qin1,2,3, Kai An1, Hongxia Liu4
1College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang road, Banan district, Chongqing 400054, China. xqqi@cqut.edu.cn.
Abstract:
Lattice oxygen substitution by nitrogen (nitridation) within the TS-1 zeolite framework has emerged as a robust strategy to enhance catalytic performance in propylene epoxidation. However, the atomic-molecular level relationship between the microstructure of Ti active centers and catalytic performance remains elusive. Herein, we provide a systematic mechanistic analysis of the nitridation effects on TS-1 catalysts comprising tetrahedral Ti, Ti-defect, and bipodal Ti sites by examining the reaction pathways for propylene epoxidation and propylene oxide (PO) solvolysis and quantifying their corresponding potential energy landscapes. Results demonstrated that nitridation simultaneously improves both PO selectivity and epoxidation activity. The enhanced epoxidation activity is primarily attributed to the tetrahedral Ti and Ti-defect sites, which gain thermodynamic and kinetic advantages in forming stable intermediates and fostering stronger propylene-intermediate interactions. Meanwhile, the improved PO selectivity is derived from a significantly higher free energy barrier required for PO ring-opening activation at the nitrided bipodal Ti sites. This mechanistic understanding not only offers profound theoretical insights into nitrogen-doped zeolites but also guides the future design of high-efficiency TS-1 catalysts for propylene epoxidation.
Related Concept Videos
Sharpless Epoxidation
Acid-Catalyzed Ring-Opening of Epoxides
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Catalysis
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Base-Catalyzed Ring-Opening of Epoxides

