Cu modified VOx/Silicalite-1 catalysts for propane dehydrogenation in CO2 atmosphere.

[Display omitted] • Cu modification to VO x /Silicalite-1 for PDH-CO 2. • Improved dispersion of VO x and tuned acidic/basic sites. • Promoted reverse water gas shift. • Highest conversion of propane/CO 2 on 0.5Cu-10VO x /S-1. Propane dehydrogenation in CO 2 atmosphere (PDH-CO 2) is of interest with a potential to raise propane conversion. Here the catalytic performance of Cu modified 10VO x /Silicalite-1(S-1) for PDH-CO 2 is presented for the first time. The initial propane conversion of 68.8% on 0.5Cu-10VO x /S-1 was reached from 59.3% on 10VO x /S-1, along with the CO 2 conversion of 44.5% from 32.4%. The role of S-1 support and Cu modification were elucidated by means of X-ray diffraction (XRD), ultraviolet–visible diffuse reflection (UV–Vis), NH 3 /CO 2 temperature-programmed desorption (NH 3 /CO 2 -TPD), H 2 temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS) characterization. While dispersing VO x , non-acidic S-1 minimized the side reactions usually occurring on the strong acidic sites. Cu modification promoted the dispersion of VO x and enabled 10VO x /S-1 exposing more weak acidic sites and basic sites, boosting respectively the adsorption of propane and CO 2 , for concurrently accelerating the reverse water gas shift (RWGS). Moreover, the highly dispersed V5+ was formed on the surface whereas the percentage of inactive V3+ decreased. [ABSTRACT FROM AUTHOR]