Coordination of Pt Single-Atom Catalysts via NMR: Experiment and Theory

In a recent article published in Nature, the authors used ¹⁹⁵Pt solid-state NMR parameters (isotropic chemical shift, δ_iso, and span, Ω; Figure 1a) to elucidate the nature of coordination environments in Pt Single-Atom Catalysts (SACs). This study highlights how the metal solid-state NMR signature encodes information on the distribution of coordination environments in SACs and showcases how extracting NMR parameters can be used to monitor the influence of the synthetic approaches on the metal sites environment, for instance to study how reproducible a synthetic protocol is, or how host materials influence Pt site structures. This methodology also enables monitoring the evolution of Pt environments during catalysis.

Computations of the NMR chemical shift tensor of Pt molecular analogues have been central to the study, they. Calculations were run in ADF 2022 with the hybrid PBE0 functional and Slater type basis sets. Relativistic effects were treated by the two component zeroth order regular approximation (ZORA). The response of the ¹⁹⁵Pt NMR parameters (δ_iso, Ω) and signatures was calculated for a series of Pt(II) square-planar model complexes with various chemical environment, evaluating the effects of N- and C-based ligands on NMR signatures. This approach based on molecular libraries enables the evaluation of the nature and the distribution of coordination environment of Pt centers, as visualized in δ_iso/ Ω two-dimensional maps (Figure 1b).