A Novel Reactive Incipient Wetness Impregnation Assisted by H 2 O 2 for Vanadium Catalysts: the Case of V/Silicalite-1 zeolites in Oxidative Propane Dehydrogenation
Year: 2026
Type: preprint
Abstract: Metal deposition in zeolites is often interpreted using concepts developed for relatively open support surfaces, overlooking the consequences of precursor transport and deposition within confined microporous environments. Here, we introduce an H 2 O 2 -mediated reactive impregnation strategy for supported vanadium catalysts reactive vanadium impregnation mediated by H 2 O 2 and that avoids organics complexing agents (carbon-free) exploiting vanadium-peroxo chemistry to dissolve in situ the precursor into smaller complexed soluble species and modify its interaction with Silicalite-1. The resulting catalyst displayed still detectable vanadium aggregates compared with conventional impregnation. The materials tested under oxidative propane dehydrogenation exhibited comparable catalytic activity (slightly higher) but improved stability during repeated reaction-regeneration cycling. The in situ coke accumulation within a cycle was tracked in the intermediary regeneration steps by using online MS, and showed similar amounts for both preparation routes, suggesting that carbon deposition is governed predominantly by the structural and pore-capacity characteristics of Silicalite-1. Structural characterization revealed distinct vanadium-support interactions in the H 2 O 2 -assisted materials, while microscopy and H2-TPR indicated different evolution of the support and vanadium phase during cycling. Under representative OPDH conditions, the H 2 O 2 -assisted catalyst reached 41% propane conversion and 90% propylene selectivity, with a 30% lower deactivation rate over ten cycles. These results identify precursor chemistry and metal-support interaction, rather than dispersion alone, as key design parameters for supported vanadium catalysts.
Source: ChemRxiv
Institutions: Sociedad de Doctores e Investigadores de Colombia, KU Leuven
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223152237