CeO2-Promoted PtSn/SiO2 as a High-Performance Catalyst for the Oxidative Dehydrogenation of Propane with Carbon Dioxide

Abstract

The oxidative dehydrogenation of propane with CO2 (CO2-ODP) has been extensively investigated as a promising green technology for the efficient production of propylene, but the lack of a high-performance catalyst is still one of the main challenges for its industrial application. In this work, an efficient catalyst for CO2-ODP was developed by adding CeO2 to PtSn/SiO2 as a promoter via the simple impregnation method. Reaction results indicate that the addition of CeO2 significantly improved the catalytic activity and propylene selectivity of the PtSn/SiO2 catalyst, and the highest space-time yield of 1.75 g(C3H6)·g(catalyst)−1·h−1 was achieved over PtSn/SiO2 with a Ce loading of 6 wt%. The correlation of the reaction results with the characterization data reveals that the introduction of CeO2 into PtSn/SiO2 not only improved the Pt dispersion but also regulated the interaction between Pt and Sn species. Thus, the essential reason for the promotional effect of CeO2 on CO2-ODP performance was rationally ascribed to the enhanced adsorption of propane and CO2 originating from the rich oxygen defects of CeO2. These important understandings are applicable in further screening of promoters for the development of a high-performance Pt-based catalyst for CO2-ODP.

Metallic Catalysts for Oxidative Dehydrogenation of Propane Using CO2

“…DFT calculations are consistent with the experimental studies (Figure 6), where the CÀ H activation energy on Fe 3 Ni (111) was lower than that of the CÀ C bond. In contrast, an opposite trend was observed for the Pt (111) and Ni 3 Pt (111). To better understand the reaction pathway of the Ni 3 Fe catalyst, the FeO-Ni interfacial active site structure was further investigated because iron oxide was observed by an in situ characterization of the Fe 3 Ni catalyst.…”

“…DFT calculations are consistent with the experimental studies (Figure 6), where the CÀ H activation energy on Fe 3 Ni (111) was lower than that of the CÀ C bond. In contrast, an opposite trend was observed for the Pt (111) and Ni 3 Pt (111).…”

“…Overall, the rapid deactivation and the lack of active sites for CO 2 remains a key issue for this catalyst. To better address this challenge, Wang et al [111] reported PtSn/SiO 2 catalysts with the addition of CeO 2 as a promoter, which could improve the catalytic activity and selectivity. As in previous studies, [15,112] CeO 2 with high oxygen storage capacity and abundant oxygen defects was chosen to activate CO 2 .…”

Revealing the Catalytic Role of Sn Dopant in CO2‐Oxidative Dehydrogenation of Propane over Pt/Sn‐CeO2 Catalyst

“…Previous work in propane dehydrogenation over ceria supported catalysts primarily focuses on the interaction between Pt and Sn species, which were introduced into ceria supports by conventional co‐impregnation method [24] . And the effects of Ce as promoter on supported PtSn catalysts were also reported [25,26] . However, understanding of the interaction among Pt, Sn species and ceria support is still limited.…”

“…[24] And the effects of Ce as promoter on supported PtSn catalysts were also reported. [25,26] However, understanding of the interaction among Pt, Sn species and ceria support is still limited. For CeO 2 -based catalysts, metal-doping has been used as an efficient way to enhance the formation of oxygen vacancies and it was found that Sn doping significantly improves the oxygen vacancy concentrations of CeO 2 in our previous work.…”