Constructing single atom catalysts with fine-tuned coordination environments can be a promising strategy to achieve satisfactory catalytic performance. Herein, via a simple calcination temperature-control strategy, CeO₂ supported Pt single atom catalysts with precisely controlled coordination environments are successfully fabricated. The joint experimental and theoretical analysis reveals that the Pt single atoms on Pt₁/CeO₂ prepared at 550 °C (Pt/CeO₂-550) are mainly located at the edge sites of CeO₂ with a Pt–O coordination number of ca. 5, while those prepared at 800 °C (Pt/CeO₂-800) are predominantly located at distorted Ce substitution sites on CeO₂ terrace with a Pt–O coordination number of ca. 4. Pt/CeO₂-550 and Pt/CeO₂-800 with different Pt₁-CeO₂ coordination environments exhibit a reversal of activity trend in CO oxidation and NH₃ oxidation due to their different privileges in reactants activation and H₂O desorption, suggesting that the catalytic performance of Pt single atom catalysts in different target reactions can be maximized by optimizing their local coordination structures.

We used angle-resolved photoemission spectroscopy (ARPES) to map out the band structure of single-layer WSe ₂ . The splitting of the top of the valence band because of spin–orbit coupling is 513 ± 10 meV, in general agreement with theoretical predictions and in the same range as that of bulk WSe ₂ . Overall, our density functional theory (DFT) calculations of the band structure are in excellent agreement with the ARPES results. We have verified that the few discrepancies between theory and experiment are not due to the effect of strain. The differences between the DFT-calculated band structure using local density approximation (LDA) and that using the generalized gradient approximation (GGA), for single-layer WSe ₂ , are caused mainly by differences in the respective charge densities.