Year: 2025
Type: article
Abstract: Significant debate remains about the site creation mechanism of heterogeneous olefin metathesis catalysts. In this work, we report how H 2 production during treatments of MoO x /SiO 2 with olefins of varying degrees of methyl substitution, contribute to differences pre-reaction active site creation. Below 500°C, increasing the olefin branching improves active site populations because these olefins can dehydrogenate into 1,3-dienes and H 2 , with excess H 2 helping facilitate MoO x reduction. At higher temperatures, olefin branching has little effect on site populations since all olefins produce H 2 via aromatization and carbon deposition reactions. Molybdenum reduction and active site creation are also accompanied by irreversible removal of silanol infrared vibrational modes. Finally, we verify our hypothesis by showing that pretreatments of co-flowed H 2 and olefins improve metathesis performance better than activation using H 2 or olefins alone.
Source: Cell Reports Physical Science
Institutions: Oregon State University, Tulane University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,620
Award: G100501782
OpenAlex ID: W4411965856