title: Surface Composition of Silver Nanocubes and Their Influence on Morphological Stabilization and Catalytic Performance in Ethylene Epoxidation.
abstract: Silver nanocubes with exposed (100) facets are reported to have improved selectivity with respect to their spherical counterparts for ethylene epoxidation. In the present study, we observe that the surface composition of the silver nanocubes also has a critical impact on activity. Detailed investigation of the surface composition of silver nanocubes has been carried out using HRTEM, SEM, EDS, EELS, and EFTEM. Surfaces of silver nanocubes are "passivated" by chloride, and its removal is essential to achieve any catalytic activity. However, the surface chloride is apparently essential for stabilizing the cubic morphology of the particles. Attempts were made to understand the competing effects of the surface species for retaining the morphology of the nanocubes and on their catalytic activity in ethylene epoxidation.
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Shiv Shankar
authors.initials: SS
authors.lastname: Sangaru
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhu
authors.affiliation: The Dow Chemical Company , 2301 N. Brazosport Blvd., Freeport, Texas 77541, United States.
authors.forename: Devon C
authors.initials: DC
authors.lastname: Rosenfeld
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Akshaya Kumar
authors.initials: AK
authors.lastname: Samal
authors.affiliation: Imaging and Characterization Lab, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Dalaver
authors.initials: D
authors.lastname: Anjum
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Basset
keywords: catalysis; ethylene epoxidation; polyol method; silver nanocubes