Propane oxidative dehydrogenation using CO₂ over CrO_x/Fe–CeO₂ catalysts

Abstract

The kinetic behavior of CrOx sites supported on Fe doped CeO2 was studied for the CO2-assissted propane oxidative dehydrogenation. The support was synthesized via a co-precipitation method of Fe and...

Recent progress in the development of catalysts for propane dehydrogenation in the presence of CO2

“…Therefore, a C 3 H 8 /CO 2 ratio of no lower than 0.6 was recommended to improve the olefin yield and catalyst lifetime. Wang et al 101 found that at relatively lower temperatures and CO 2 /C 3 H 8 ratios, selective dehydrogenation pathways are kinetically more favorable over 3 wt% CrO x /10Fe-CeO 2 , where Cr-O and CrO can be regarded as surface oxygen sites for propane adsorption, and then the generated oxygen defects/vacancies are replenished by CO 2 . In addition, they found that the rate of propane consumption tends to be unaffected by CO 2 , but the rate of propene formation decreases monotonically with an increase in CO 2 , which indicates that propane dry reforming become favorable under high CO 2 /C 3 H 8 conditions.…”

“…6). Wang et al 101 found that the incorporation of trivalent Fe in the CeO 2 support facilitated the generation of more active lattice oxygen, which could react with hydrocarbon species (CH x ) and help to reduce the possibility of atomic carbon formation and enhance the stability of Cr/Fe–CeO 2 catalysts in CO 2 -OPDH (Table 2).…”

Insight into the Reaction Mechanism and Deactivation during CO2-Assisted Propane ODH over VOx/TiO2 Catalysts: An Operando Spectroscopic Study

“…Overall, the initial values of propane and CO2 conversions in combination with the propylene selectivities are at a higher level than those of other VOx-based catalyst systems, [23][24][25]27 and even reach those of some of the supported CrOx systems. 18,21,40 Figures 2b and c depict the time-dependent conversions of C3H8 and CO2 for the P25-based samples. As shown in Figure 2b, the propane conversion is significantly higher at the beginning of the reaction, which is most pronounced for the samples loaded with 1.2 and 2.5 V/nm².…”

“…[14][15][16][17] In the past, a research focus was put on chromium oxide (CrOx) due to its high activity. 7,[18][19][20][21] In this context, Mychorczyk et al 20 described the oxidation state of chromium, as measured via operando UV-Vis spectroscopy, to be of great importance to differentiate between the oxidative and nonoxidative reaction paths, where Cr 6+ species are reduced rapidly to Cr 2+/3+ species under reaction conditions, which participate in the non-oxidative pathway. However, as chromium oxides are toxic and harmful to the environment, other materials have attracted renewed interest.…”