This README focuses exclusively on GC and micro-GC investigations. The data are organized into two folders (`Lab_micro-GC` and `Synchrotron_GC`), one Origin project file (`final_IPO_GC_microGC.opju`) included also as.csv for vendor-independent use(`final_IPO_GC_microGC_MicroGC.csv and final_IPO_GC_microGC_Snychrotron-GC.csv`) and this Readme document.



1. Lab_micro-GC

This folder contains experimental data and evaluation results from micro-GC gas analysis carried out on an m-XRD cell under laboratory conditions (at 515°C and 1 bar pressure).

I. `20251119_CRC1615_B02_Lab_micro-GC_diff_positions_raw.xlsx`

This file contains spatially resolved raw data obtained from micro-GC measurements. All raw data are additionally provided as .csv for vendor-independent use.

The following gas species were directly measured:
O₂
N₂
C₂H₄
CO₂
C₂H₆
H₂

Measurements were performed using different micro-GC channels. Gas species were identified based on their retention times. Each sheet corresponds to a specific reactor position (0-45 mm).



II. `final_Lab_micro-GC_evaluation.xlsx`

This file contains 'processed and evaluated data', including spatial corrections and molar flow calculations.

=>Position correction

The original reactor length ranges from 0 to 55 mm. The first and last 5 mm correspond to quartz wool plugs and are not part of the active bed.

To define the effective catalytic bed:

A correction of −5 mm was applied to the original position.
A new column (`New position`) was created.

=>Molar flow calculation

Measured peak areas of O₂, N₂, C₂H₄, CO₂, C₂H₆, and H₂ were converted into molar flow rates (mmol/min) using the following steps:

=> Area normalization
Peak areas were normalized by dividing each species area by the inert gas area at the corresponding position.

=> Conversion to volumetric flow rate (mL/min)
Normalized areas were converted to flow rates using GC calibration curves of the form:
y₂ / y₁ = m (x₂ / x₁)
where y₂ / y₁ is the ratio of flow rates, x₂ / x₁ is the ratio of peak areas, and m is the calibration slope.

=> Unit conversion
Volumetric flow rates were converted from mL/min to m³/min.

=> Conversion to molar flow rate
Molar flow rates were calculated using the ideal gas law:

n = PV/RT


=> Atomic balance method

The molar flow rates of unmeasured species (H₂O, CO, and CH₄) were determined using elemental balances.
Rows represent elements: N, H, O, C
Columns represent species: N₂, H₂, H₂O, CO, CO₂, C₂H₆, C₂H₄, O₂

E =[ 2  0  0  0  0  0  0  0 
     0  2  2  0  0  6  4  0 
     0  0  1  1  2  0  0  2 
     0  0  0  1  1  2  2  0]

This matrix enforces elemental conservation and enables calculation of the unknown molar flow rates.


Notes

All molar flow rates are reported in mmol/min.
Spatial positions correspond to the effective catalytic bed after correction.
Ensure consistency between raw and processed datasets during further analysis.



2. Synchrotron_GC

This folder includes a processed evaluation file with results from GC gas analysis conducted on an m-XRD cell at 530°C and 1 bar pressure in a synchrotron.

I.`finalsynchrotronGC_evaluation.xlsx`
The raw data were processed using a different GC system at the synchrotron, resulting in retention times that differ from laboratory micro-GC measurements. All raw data are additionally provided as .csv for vendor-independent use.
Gas analysis of the spatial profile in the m-XRD cell at the synchrotron included direct measurement of:

O₂
N₂
C₂H₄
CO₂
C₂H₆
CO
CH₄

Only H₂ and H₂O were calculated using elemental (atomic) balances.

3.  Origin project file

File: `final_IPO_GC_microGC.opju`. Origin worksheet is additionally provided as  "final_IPO_GC_microGC_MicroGC.csv" and "final_IPO_GC_microGC_Snychrotron-GC.csv" for vendor-independent use.

This Origin project file was used to generate Figure 2.

=>Data structure and workflow

Processed data were organized into two sheets:

 Lab_micro-GC
 Synchrotron_GC
 
Both datasets are stored in the workbook "FinalGC Data".
 A single X-column (`New position`) is used.
 Multiple Y-columns represent molar flow rates of different species.

4. File Naming Convention:
Example filename: 20251119_CRC1615_B02_Lab_micro-GC_0mm.asc
- YYYYMMDD: Date of creation
- CRC1615: Research project
- B02: Subproject identifier
- Lab_micro-GC: Measurement method
- _0mm: Position of the catalyst in the reactor

Number of Records:
GC_data: 37 files, 664 KB in total

5. Access and Licensing Information

Repository and Persistent Identifier:
Published via TORE, DOI: https://doi.org/10.15480/882.15279

License for Use:
- Raw data files (.asc, .opju, .xlsx, .csv): Public Domain Mark (PDM)
- Figures (.png): CC BY 4.0

Access Restrictions:
Open access

Text for Citation:

For raw data (Public Domain):
G. Gizer, H. M. Zeeshan,
"IPO-XRD Data for Oxidative Dehydrogenation of Ethane over MoO3/γ-Al2O3",
Hamburg University of Technology (TUHH), 2026,
DOI: https://doi.org/10.15480/882.15279

For figures (CC BY 4.0):
G. Gizer, H. M. Zeeshan, et al.,
"Iso-Potential Operando X-Ray Diffraction (IPO-XRD) – Figures Illustrating Catalyst Dynamics",
Hamburg University of Technology (TUHH), 2026,
DOI: https://doi.org/10.15480/882.15279

6. Reproducibility and Software Dependencies

Software Required:
- Origin 2025b (.opju files)
- Microsoft Excel or compatible software (.xlsx files)
- Any text editor or spreadsheet software for .csv files
- Image viewer for .png files

Scripts and Workflow:
Data processing scripts are included in .opju files. Analyses can be reproduced using .csv files with standard spreadsheet or analysis software.

Reproducibility Notes:
Key results from the related publication can be reproduced by comparing XRD phase transitions with gas-phase composition data under the reported experimental conditions.

7. Ethical and Legal Aspects
Data Protection:
No personal or sensitive data included; not applicable.

Consent Statement:
Not applicable

8. Versioning and Updates
Version Number:
v1.0

Date of Release:
2026-04-08

Change Log:
Initial release

9. Contact Information
Corresponding Author:
Name: Raimund Horn
Institution: Hamburg University of Technology (TUHH)
Email: horn@tuhh.de
ORCID: 0000-0001-8457-3161
Project Website: https://www.tuhh.de/sfb1615/