Spherical P‐modified catalysts for heterogeneous cross‐aldol condensation of formaldehyde with methyl acetate for methyl acrylate production
Bibliographic record
Abstract
Abstract A series of spherical supported catalysts were prepared for the production of methyl acrylate (MA) via cross‐aldol condensation with methyl acetate (MeOAc) and formaldehyde—the simplest aldehyde without α‐H. ZSM‐5, γ‐Al2O3, MCM‐41, SBA‐15, and β‐zeolite were used as supports and phosphorus element (P) was selected for the active component to synthesize the catalyst to study the influence of the catalyst acid‐base properties on the yield of MA. The catalyst was characterized with X‐ray diffraction, XPS, Pyridine FTIR, BET, SEM, TEM, CO2‐TPD, and NH3‐TPD and the changes of the catalyst structure and acid properties were explored. The results showed the carbonyl polarity of methyl acetate was boosted by Lewis acid sites (L acid) and the formaldehyde activation and formation of ester enol form could be promoted by Bronsted acid sites (B acid). Using the fixed‐bed reactor, the effect of calcination temperature, catalyst loading, reaction temperature, molar ratio of reactants, and sources of phosphorus were optimized, then the catalyst life and regeneration performance were also evaluated. Lastly, the catalytic mechanism of P‐modified ZSM‐5 catalysts was proposed.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".