Modification of N<scp>A</scp>Y by L<scp>A</scp><sup>3+</sup> for the dehydration of lactic acid: The effect of preparation protocol on catalyst microstructure and catalytic performance
Bibliographic record
Abstract
Abstract La‐modified NaY zeolites have been prepared through impregnation and in situ synthesis methods. The surface structure of the obtained zeolites was then characterised by XRD, UV–Vis DRS, FT‐Far‐IR, Raman spectra, H2‐TPR, N2 adsorption, and NH3‐TPD. The results of the catalytic dehydration reaction of lactic acid showed that the La/NaY catalyst prepared by impregnation method exhibited higher selectivity to acrylic acid than the La–NaY prepared by the in situ synthesis. The characterisation results indicated that the enhanced catalytic performance could be attributed to the difference of La3+ ion location caused by the different preparation protocols, which would influence the electric field distribution of zeolites cages, the reactant adsorption, chemical activation, and the reaction path. Les zéolithes NaY modifiées avec du lanthane (La) ont été préparées grâce à des méthodes d'imprégnation et de synthèse in situ. La structure de la surface des zéolithes ainsi obtenues a été ensuite caractérisée par DRX, spectrophotomètre UV–VIS DR, FT‐Far‐IR, spectroscopie Raman, réduction thermo‐programmée de H2, adsorption de N2 et désorption thermo‐programmée de NH3. Les résultats de la réaction de déshydratation catalytique de l'acide lactique montrent que le catalyseur La/NAY préparé grâce à la méthode d'imprégnation a fait preuve d'une plus grande sélectivité à l'acide acrylique que le catalyseur La/NAY préparé grâce à la synthèse in situ. Les résultats de caractérisation indiquent que le meilleur rendement catalytique peut être dû aux différences d'emplacement de l'ion La3+ causées par les différents protocoles de préparation, qui peuvent influer sur la distribution du champ électrique des cages de zéolithes, l'adsorption du réactif, l'activation chimique et le chemin réactionnel. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering
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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".