Thermally Stable Alkylidene Groups on the Surface of β-Mo<sub>2</sub>C: Relevance to Methane Aromatization and Olefin−Metathesis Catalysis
Bibliographic record
Abstract
A combination of surface spectroscopy and chemical reactivity studies was used to show that alkylidene groups, formed on β-Mo 2 C through the dissociative adsorption of ketones, are stable under ultrahigh vacuum conditions to anomalously high temperatures. Results are presented for cyclobutylidene, cyclopentylidene, and cyclohexylidene. Reflectance absorbance infrared spectroscopy in the CH 2 stretching region, high-resolution X-ray photoemission measurements, labeled oxygen insertion, and metathesis reactions were used to detect surface alkylidenes at or above 900 K. The anomalous thermal stability of alkylidenes on the carbide surface shows that carbenes may be present on the carbide phase of Mo/ZSM-5 catalysts during the methane dehydroaromatization reaction. The latter reaction is typically carried out at approximately 970 K.
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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 | 0.001 | 0.000 |
| 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) | 0.000 | 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".