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

Abstract

Propane dehydrogenation in CO2 atmosphere (PDH-CO2) is of interest with a potential to raise propane conversion. Here the catalytic performance of Cu modified 10VOx/Silicalite-1(S-1) for PDH-CO2 is presented for the first time. The initial propane conversion of 68.8% on 0.5Cu-10VOx/S-1 was reached from 59.3% on 10VOx/S-1, along with the CO2 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), NH3/CO2 temperature-programmed desorption (NH3/CO2-TPD), H2 temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS) characterization. While dispersing VOx, non-acidic S-1 minimized the side reactions usually occurring on the strong acidic sites. Cu modification promoted the dispersion of VOx and enabled 10VOx/S-1 exposing more weak acidic sites and basic sites, boosting respectively the adsorption of propane and CO2, 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.