Enhancing the syngas production yield from ethane and CO₂ by optimizing the Pd-O-Ce interface

CO₂-assisted oxidative dehydrogenation of ethane (CO₂-ODHE) and dry reforming of ethane (DRE) have provided a promising way to simultaneously upgrade CO₂ and ethane to produce value-added industrial feedstocks, such as syngas (CO and H₂), or ethylene. CeO₂-supported Pd bimetallic catalysts have been demonstrated to be efficient catalysts for these reactions. In particular, the Pd-O-Ce interface and Pd-O-Fe (or Pd-O-In) interface were verified as the key active sites for producing syngas and ethylene, respectively. However, how to regulate the amount of interface to further enhance the product yield is still a major challenge in this area. In this study, we show that the ratio of the Pd-O-Ce interface can be optimized through the CeO₂ nano-island strategy. CeO₂ nano-islands with different loadings and sizes are grafted onto the high-surface-area SiO₂, and are then used for anchoring PdFe_n bi-metals, thus leading to the formation of interfaces with different amounts of Pd-O-Ce. The results show that when the Ce loading reaches 15 wt%, the supported PdFe_n catalyst has the highest ratio at the Pd-O-Ce interface, resulting in a significant increase in the syngas yield (879.1μmol · g^-1 · min^-1for CO and 508.1μmol · g^-1 · min^-1 for H₂ respectively), which is the best among all the reported state-of-the-art catalysts in the literature. At the same time, the ethylene production rate can be maintained at a high level of 172.5 μmol · g^-1 · min^-1.