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Controlling the Oxidation State of Pt Single Atoms for Maximizing Catalytic Activity |
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| Authors: | Hojin Jeong Dongjae Shin Beom-Sik Kim Junemin Bae Sangyong Shin Chanyeong Choe Prof. Jeong Woo Han Prof. Hyunjoo Lee |
| Affiliation: | 1. Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141 Republic of Korea These authors contributed equally to this work.;2. Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673 Republic of Korea These authors contributed equally to this work.;3. Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141 Republic of Korea;4. Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673 Republic of Korea |
| Abstract: | Single-atom catalysts (SACs) have emerged as promising materials in heterogeneous catalysis. Previous studies reported controversial results about the relative level in activity for SACs and nanoparticles (NPs). These works have focused on the effect of metal atom arrangement, without considering the oxidation state of the SACs. Here, we immobilized Pt single atoms on defective ceria and controlled the oxidation state of Pt SACs, from highly oxidized (Pt0: 16.6 at %) to highly metallic states (Pt0: 83.8 at %). The Pt SACs with controlled oxidation states were then employed for oxidation of CO, CH4, or NO, and their activities compared with those of Pt NPs. The highly oxidized Pt SACs presented poorer activities than Pt NPs, whereas metallic Pt SACs showed higher activities. The Pt SAC reduced at 300 °C showed the highest activity for all the oxidations. The Pt SACs with controlled oxidation states revealed a crucial missing link between activity and SACs. |
| Keywords: | ceria CO oxidation oxidation state platinum single-atom catalysts (SACs) |