{"title":"Calcium hydroxide aerogels and xerogels toward CO2 fixation: through an epoxide-mediated sol-gel reaction","authors":"Ryota Kobayashi, Shintaro Fujinari, Yasuaki Tokudome, Atsushi Nakahira","doi":"10.1007/s10971-024-06497-4","DOIUrl":null,"url":null,"abstract":"<p>Calcium-based CO<sub>2</sub> sorbents have garnered attention due to the capability of CO<sub>2</sub> separation through a process based on carbonation-calcination reaction from flue gas. Ca-based materials with high porosity, allowing for CO<sub>2</sub> diffusion and tolerance for volume change upon carbonation, would be promising for carbon capture and storage (CCS) applications. The present study focused on developing Ca-based aerogels and xerogels prepared through a sol-gel reaction toward CCS application. Calcium hydroxide aerogels and xerogels, which transform into CaO at a high temperature, were prepared through the epoxide-mediated sol-gel reaction using propylene oxide (PO). Two types of carboxylic acids, poly acrylic acid (PAA) and malonic acid (MA), were employed to inhibit the extensive crystal growth of calcium hydroxide in the initial step of the alkalization reaction induced by PO, resulting in the formation of nanocrystalline aerogels and xerogels through supercritical and ambient drying, respectively. The present systematic study revealed that the obtained xerogels prepared with MA exhibit relatively high CO<sub>2</sub> fixation characteristics thanks to the unique card-house nanostructure allowing for the formation of high porosity.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Sol-Gel Science and Technology","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1007/s10971-024-06497-4","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Calcium-based CO2 sorbents have garnered attention due to the capability of CO2 separation through a process based on carbonation-calcination reaction from flue gas. Ca-based materials with high porosity, allowing for CO2 diffusion and tolerance for volume change upon carbonation, would be promising for carbon capture and storage (CCS) applications. The present study focused on developing Ca-based aerogels and xerogels prepared through a sol-gel reaction toward CCS application. Calcium hydroxide aerogels and xerogels, which transform into CaO at a high temperature, were prepared through the epoxide-mediated sol-gel reaction using propylene oxide (PO). Two types of carboxylic acids, poly acrylic acid (PAA) and malonic acid (MA), were employed to inhibit the extensive crystal growth of calcium hydroxide in the initial step of the alkalization reaction induced by PO, resulting in the formation of nanocrystalline aerogels and xerogels through supercritical and ambient drying, respectively. The present systematic study revealed that the obtained xerogels prepared with MA exhibit relatively high CO2 fixation characteristics thanks to the unique card-house nanostructure allowing for the formation of high porosity.
钙基二氧化碳吸附剂由于能够通过基于烟气碳化-钙化反应的过程分离二氧化碳而备受关注。钙基材料具有高孔隙率,允许二氧化碳扩散,并能承受碳化时的体积变化,因此在碳捕集与封存(CCS)应用中大有可为。本研究的重点是开发通过溶胶-凝胶反应制备的钙基气凝胶和气凝胶,以实现 CCS 应用。研究人员利用环氧丙烷(PO)通过环氧化物介导的溶胶-凝胶反应制备了氢氧化钙气凝胶和异凝胶,它们在高温下会转化为 CaO。在 PO 诱导的碱化反应初始阶段,采用聚丙烯酸(PAA)和丙二酸(MA)这两种羧酸来抑制氢氧化钙的大量晶体生长,从而分别通过超临界干燥和常温干燥形成了纳米结晶的气凝胶和异凝胶。本系统研究表明,用 MA 制备的 xerogels 具有较高的二氧化碳固定特性,这要归功于其独特的卡室纳米结构,这种结构允许形成高孔隙率。
期刊介绍:
The primary objective of the Journal of Sol-Gel Science and Technology (JSST), the official journal of the International Sol-Gel Society, is to provide an international forum for the dissemination of scientific, technological, and general knowledge about materials processed by chemical nanotechnologies known as the "sol-gel" process. The materials of interest include gels, gel-derived glasses, ceramics in form of nano- and micro-powders, bulk, fibres, thin films and coatings as well as more recent materials such as hybrid organic-inorganic materials and composites. Such materials exhibit a wide range of optical, electronic, magnetic, chemical, environmental, and biomedical properties and functionalities. Methods for producing sol-gel-derived materials and the industrial uses of these materials are also of great interest.