透過矽烷偶合反應對金屬有機骨架進行疏水性修飾並應用於二氧化碳捕捉

Abstract

MOFs因優秀的吸附能力、吸附選擇性及再生性，使其在捕獲二氧化碳十分有前景。然而，由於MOFs對於水氣的低穩定性及水與二氧化碳產生的競爭吸附，極大程度的影響其在真實煙道氣環境下的二氧化碳吸附量及選擇性。現今科學家們致力於研究各種策略去降低水氣對於MOF的影響，研究結果顯示，增加MOF的疏水性是一種有效降低水氣影響的方法。在本研究中，經過矽烷化合物的合成後修飾及乙醚洗滌的過程後，所選用的MOF均由親水性轉變為疏水性物質，且仍保有其二氧化碳捕捉能力，分別為:MIL-160的WCA從16 o變為148 o；MOF-303的WCA從13 o變為141 o；MIL-53-TDC的WCA從20 o變為136 o；CAU-23的WCA從14 o變為132 o。二氧化碳捕捉能力則分別為:MIL-160從原本的3.64變為3.69 mmol/g；MOF-303從原本的5.06變為4.47 mmol/g；MIL-53-TDC從原本的2.11變為2.63 mmol/g；CAU-23修飾前後數值不變，均為3.08 mmol/g。MOFs are considered to have great potential in capturing CO2 due to their excellent adsorption capacity, selectivity, and regenerability. However, the MOF’s low stability of H2O and the competitive adsorption between H2Oand CO2 significantly impact their CO2 adsorption capacity and selectivity in flue gas environments. Currently, scientists are striving to study various strategies to mitigate the impact of moisture on MOFs, and Many paper show that increasing the hydrophobicity of MOFs is an effective approach.In this study, through the post-modification with silane compounds, and ether washing process, the hydrophilic MOFs have transformed to hydrophobic materials while still retaining their CO2 adsorption capabilities. The WCA of MIL-160 increased from 16 o to 148 o; MOF-303 increased from 13 o to 141 o; MIL-53-TDC increased from 20 o to 136 o; CAU-23 increased from 14 o to 132 o. The CO2 adsorption capacities are as follows: MIL-160 increased from 3.64 mmol/g to 3.69 mmol/g; MOF-303 decreased from 5.06 mmol/g to 4.47 mmol/g; MIL-53-TDC increased from 2.11 mmol/g to 2.63 mmol/g; CAU-23 remained unchanged at 3.08 mmol/g before and after modification.