γ-alumina is the most studied metastable phase of the alumina. It is recognized as a strategic material in many industrial processes, acting as adsorbent, catalyst or support due to its high surface area, thermal and chemical stability. Its heterogeneous surface imposes a challenge for characterization by adsorption. The use of experimental adsorption data, combined with the theoretical approach of molecular simulation is becoming the standard adsorption-based technique to characterization. Therefore, this study aims to launch a first insight in the performance of the atom–atom (AA) and united-atom (UA) molecular models of the CO₂, a probe gas less prone to diffusion limitations, given the lack of an appropriate kernel for the γ-alumina characterization. A detailed experimental isotherm of CO2 in γ-alumina was performed and a collection of isotherms was calculated applying Monte Carlo method in the grand canonical ensemble. To build the kernel, isotherm in 10 different slit-pore sizes were calculated. The different pore filing regimes result in a kernel with good reliability window. With these CO₂ kernels (AA and AU models), reasonable pore size distributions were predicted, capturing the low range of microporosity. Additional assessment with others probes gas is recommended to confirm the feasibility of CO₂ as a characterizing molecule.

γ-氧化铝是氧化铝中研究最多的亚稳态相。由于其高表面积、热稳定性和化学稳定性，它被公认为许多工业过程中的战略材料，可用作吸附剂、催化剂或载体。其异质表面对吸附表征提出了挑战。使用实验吸附数据，结合分子模拟的理论方法正在成为标准的基于吸附的表征技术。因此，本研究旨在首次了解 CO ₂的原子-原子 (AA) 和联合原子 (UA) 分子模型的性能。，考虑到缺乏用于 γ-氧化铝表征的合适内核，探针气体不太容易受到扩散限制。进行了 γ-氧化铝中 CO2 的详细实验等温线，并在正则系综中应用蒙特卡罗方法计算了一组等温线。为了构建内核，计算了 10 种不同狭缝孔径的等温线。不同的孔隙填充机制导致内核具有良好的可靠性窗口。使用这些 CO ₂内核（AA 和 AU 模型），可以预测合理的孔径分布，捕获低范围的微孔率。建议与其他探测气体进行额外评估，以确认 CO ₂作为表征分子的可行性。