Work

Role of silanol groups and hydrothermal rehydroxylation on the functionalization of SBA-15 with APTES for CO2 capture

Year: 2025

Type: article

Abstract: In order to find the best initial characteristics of an APTES-functionalized SBA-15 material, a group of SBA-15 materials was synthesized. Firstly, to remove the template, two methods were employed: i) water and ethanol washing method, and ii) calcination method where three calcination temperatures were explored (350, 450 and 550 °C), all carried out in a constant air flow. The purpose of avoiding calcination of the material is to prevent the loss of silanol groups, which are involved in chemical modification with amino groups. And secondly, a portion of these materials were subjected to a hydrothermal process to improve the amount of surface silanol groups, groups on which APTES molecules are anchored. In this way, 8 materials were obtained that were then functionalized with APTES. Based on the nitrogen adsorption isotherms, an increase in pore size was observed when the material is rehydroxylated, which demonstrates the formation of silanol groups. And when the materials are functionalized, the average pore size decreases by about 1.0 nm, indicating the probability of the formation of new bonds between the surface silanol groups with the ethoxy groups of the APTES molecule. The CO2 uptake capacity showed interesting results for most of the materials, with the uncalcined materials presenting the highest values, 2.52 and 2.32 mmol g-1 at 1 bar and 25 ºC for S15WC-F and S15WC-FR, respectively.

Source: Microporous and Mesoporous Materials

DOI: 10.1016/j.micromeso.2025.113597

Authors: Reyna Ojeda-López, J. Marcos Esparza-Schulz, Isaac J. Pérez-Hermosillo, Enrique Vilarrasa-García, Enrique Rodriguez-Castellón

Institutions: Universidad Autónoma Metropolitana, Tecnológico Nacional de México, Universidade Federal do Ceará, Universidad de Málaga

Language: English

Topic: Carbon Dioxide Capture Technologies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Climate action

Open Access status: hybrid

Estimated APC paid: $3,970