Alumina-coated ordered mesoporous silica as an efficient and stable water adsorbent for adsorption heat pump

• Published in: Microporous and mesoporous materials 2017-02, Vol.239, p.310-315
• Main Authors: Kim, Chaehoon, Cho, Kanghee, Kim, Sang Kyum, Lee, Eun Kyung, Kim, Jong-Nam, Choi, Minkee
• Format: Article
• Language: English
• Subjects: Adsorption heat pump; Alumina; Hydrothermal stability; Mesoporous silica; Water adsorption
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2016.10.014

With regard to the large amount of available but unused low-temperature heat ( 0.3, which is too high for AHP. This indicates that the pore diameter should be further reduced below the typical mesopore diameter range of these materials. Another serious limitation of these materials as a water adsorbent is their low hydrothermal stability. In this work, in order to reduce the mesopore diameter and to increase the hydrothermal stability of MCM-41 simultaneously, the silica mesopore surface was uniformly coated with an alumina layer. Due to the reduced mesopore size (2.05 nm), the alumina-coated MCM-41 showed S-shaped water isotherm with capillary condensation in the ideal P/Po range of 0.1–0.3. The adsorbent also showed remarkably enhanced hydrothermal stability. Consequently, the adsorbent showed a cycling water capacity of 0.27 gwater gads−1 (1.5 times larger than FAM-Z01 which is a commercialized adsorbent for AHP) without a loss of capacity up to 10 cycles. [Display omitted] •Alumina-coated MCM-41 was synthesized as a H2O adsorbent for adsorption heat pump.•The mesopore size was reduced to 2.05 nm by the alumina coating on MCM-41.•Hydrothermal stability was remarkably enhanced after the alumina coating.•The adsorbent showed ideal H2O capillary condensation in 0.1