Climate change is currently having disastrous consequences on ecosystems. One of the most prevalent greenhouse gasses that contributes to climate change is CO₂. It is critical that steps are taken to mitigate this climate change through CO₂ utilization. The primary goal of this study is to convert CO₂ to value-added chemicals, such as light olefins. In this work, we reported the synthesis of a unique Fe₂O₃ supported Pd-Pt bimetallic catalysts at varying Pd loadings (0.001~2 wt%). Specifically, the metallic Pd-Pt colloid was prepared by utilizing a proprietery anchoring agent to form an organometallic complex with Pd²⁺ and Pt²⁺, followed by hydrogen reduction. The above colloid was impregnated with Fe₂O₃ using rota-vap. The dried samples were calcined and compressed into uniform particle size prior to testing. The synthesized catalysts were tested for CO₂ hydrogenation through a flow bed reactor at controlled temperatures and CO₂/H₂ flow rate. The products were analyzed using on-line gas chromatography (GC) to determine the catalytic performance (selectivity and CO₂ conversion). The testing results exhibited intriguing selectivity for light olefins at exceptionally low Pd loading (0.01 wt%). This incredible result sheds lights on economic feasibility of potential commercial development for CO₂ conversion. The catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to establish relationships between activity and properties. This unique Pd-Pt bimetallic catalysts can provide substantial insights into understanding the role of the anchoring agent, Pd, Pt and Fe in the reaction pathway for CO₂ conversion.

Heran Zhang

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