Catalytic Process for the Conversion of Halon 1211 (CBrClF<sub>2</sub>) to Halon 1301 (CBrF<sub>3</sub>) and CFC 13 (CClF<sub>3</sub>)
Bibliographic record
Abstract
This paper reports the catalytic pyrolysis of CBrClF 2 over γ -Al 2 O 3 and β -AlF 3 in a plug-flow reactor operated at atmospheric pressure and within the temperature window of 523−673 K. The results indicate a very high conversion of halon 1211, in excess of 90% for γ -Al 2 O 3 and 60−80% for β -AlF 3, over the entire temperature range. Halon 1301 (CBrF 3 ) and CFC 13 (CClF 3 ) are the main pyrolysis products, although their yields vary with temperature and catalyst type. If accepted by regulators, this process offers a reaction pathway for converting stockpiled halon 1211 into more widely used halon 1301. A mechanistic interpretation of the results is proposed, including the reaction pathways and the transformations taking place in the catalysts. The mechanism involves the initial activation of the catalysts, which is reflected by the formation of the surface aluminum fluoride species identified by XRD analysis. This species then facilitates the halogen exchange between Br and Cl in CBrClF 2 and F in the catalyst framework, leading to the formation of CBrF 3 and CClF 3 . It is also proposed that two minor species (CBr 2 F 2 and CCl 2 F 2 ) are formed by dismutation of CBrClF 2 .
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.003 |
| 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; both teacher heads agree on what is shown here.
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".