CO<sub>2</sub> and H<sub>2</sub>O Sorption Induced Bulk-Phase Changes of CALF-20 Captured Using <i>In Situ</i> Laboratory X-ray Powder Diffraction
Bibliographic record
Abstract
High Resolution Image Download MS PowerPoint Slide The zinc oxalate (ox) triazolate (trz)-based MOF, Calgary Framework 20 (CALF-20), exhibits remarkable cycling stability for carbon dioxide and water adsorption and desorption and is therefore a promising candidate material for CO 2 sequestration on an industrial scale. Upon gas and vapor loading and unloading, the MOF shows pronounced structural dynamics leading to a variety of potential CALF-20 polymorphs. A systematic in situ study on CO 2 and H 2 O ad- and desorption using high-resolution, laboratory X-ray powder diffraction (XRPD) shows that the CO 2 -breathing behavior changes upon gas loading. A CO 2 uptake initially distorts the rectangular pore into a diamond shape. Upon further CO 2 incorporation, the breathing behavior changes, and the pore becomes more rectangular, again. At low temperatures (−70 °C), the uptake of CO 2 occurs in a core–shell mechanism, and the gas is bound strongly to the framework and cannot be removed by dynamic vacuum. During water uptake of CALF-20, two distinct hydrated phases can be identified. The overall water loading capacity is independent of temperature between 25 and 60 °C. In this paper, we demonstrate that recent advances in X-ray powder diffraction hard- and software enable a detailed investigation of the loading and breathing behavior of a crystalline MOF using laboratory equipment, turning this into easily accessible investigations.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.002 | 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".