X-ray Photoelectron Spectroscopy and the Auger Parameter As Tools for Characterization of Silica-Supported Pd Catalysts for the Suzuki−Miyaura Reaction
Bibliographic record
Abstract
Palladium has been immobilized on thiol-modified mesoporous and amorphous silicates and used as a catalyst for the Suzuki−Miyaura reaction. Heterogeneous catalysts are difficult to characterize due to the difficulty of applying traditional solution state characterization methods like NMR to solid samples. As such, the catalysts are often poorly understood. In an effort to better understand the oxidation state and electronic environment of both the reactive palladium center and the thiol ligands through which it is bound in the catalyst, we characterized a wide range of both Suzuki−Miyaura catalysts and Pd compounds by both X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger spectroscopy (XAES) focusing on Pd, S, and Si. The use of XAES data allows determination of the Auger parameter for Pd and S, which provides information not only on oxidation state but also on the polarizability of the surrounding ligands in the catalyst. Changes in XPS binding energy and XAES kinetic energy are discussed particularly in terms of the nature of the reactive Pd center before and after use, and the effects on the S ligand as a function of Pd loading.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".