Nickel promotes selective ethylene epoxidation on silver

• 成果类型: Article
• 署名作者: Jalil, Anika; Happel, Elizabeth E.; Cramer, Laura; Hunt, Adrian; Hoffman, Adam S.; Waluyo, Iradwikanari; Montemore, Matthew M.; Christopher, Phillip; Sykes, E. Charles H.
• 署名单位: University of California System; University of California Santa Barbara; Tufts University; United States Department of Energy (DOE); Brookhaven National Laboratory; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; Tulane University; Tufts University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10916
• DOI: 10.1126/science.adt1213
• 发表日期: 2025-02-21
• 页码: 869-873
• 关键词: x-ray photoelectron; bimetallic catalysts; oxygen; oxidation; ag(111); ag; surface; DESIGN; cs; co

摘要

Over the last 80 years, chlorine (Cl) has been the primary promoter of the ethylene epoxidation reaction valued at similar to 40 billion USD per year, providing a similar to 25% selectivity increase over unpromoted silver (Ag) (similar to 55%). Promoters such as cesium, rhenium, and molybdenum each add a few percent of selectivity enhancements to achieve 90% overall, but their codependence on Cl makes optimizing and understanding their function complex. We took a theory-guided, single-atom alloy approach to identify nickel (Ni) as a dopant in Ag that can facilitate selective oxidation by activating molecular oxygen (O-2) without binding oxygen (O) too strongly. Surface science experiments confirmed the facile adsorption/desorption of O-2 on NiAg, as well as demonstrating that Ni serves to stabilize unselective nucleophilic oxygen. Supported Ag catalyst studies revealed that the addition of Ni in a 1:200 Ni to Ag atomic ratio provides a similar to 25% selectivity increase without the need for Cl co-flow and acts cooperatively with Cl, resulting in a further 10% initial increase in selectivity.