苯甲酸型低共熔溶剂吸收一氧化氮的性能研究

Study on the absorption of nitric oxide by benzoic acid-based deep eutectic solvents

低共熔溶剂(DESs)已被广泛研究并应用于酸性气体的吸收,本研究发现苯甲酸类DESs能够可逆高效地吸收一氧化氮(NO)。以苯甲酸(BA)、硫脲、尿素和咪唑为氢键供体(HBD),以离子液体为氢键受体(HBA)制备了一系列的DESs。吸收NO的实验结果表明,以氯化四丁基膦(P4444Cl)为HBA和以BA为HBD的DESs表现出较高的NO吸收速率和饱和吸收量。BA/P4444Cl(1∶2)DES在101.3 kPa、303.15 K下,NO吸收量为2.75 mol/mol。热重测试和再生实验的结果表明,BA/P4444Cl(1∶2)DES具有理想的热稳定性和重复使用性。通过FTIR、1H NMR和高斯模拟计算,探讨了BA/P4444Cl(1∶2)DES对NO的吸收机理,发现NO与BA的含氢氧原子之间存在化学相互作用,且BA的易去质子化性质有利于NO的吸收。

Deep eutectic solvents(DESs)have been extensively studied and applied to the absorption of acid gases.This study found that benzoic acid DESs can reversibly and efficiently absorb nitric oxide(NO).A series of DESs based on benzoic acid(BA),thiourea,urea,imidazole as hydrogen bond donors(HBDs)and ionic liquids as hydrogen bond acceptors(HBAs)were prepared.The NO absorption results showed that DESs based by tetrabutylphosphine chloride(P4444Cl)as HBA and BA as HBD exhibited the higher NO absorption rate and NO equilibrium absorption.BA/P4444Cl(1∶2)DES exhibited the NO absorption of 2.75 mol/mol at 101.3 kPa and 303.15 K.The NO absorption capacity decreased continuously with the increasing temperature.The results of TGA measurement and regeneration experiments demonstrated that BA/P4444Cl(1∶2)DES possessed desirable thermostability and reusability.The absorption mechanism of NO by BA/P4444Cl(1∶2)DES was studied by FTIR,1H NMR and Gaussian simulations.It was found that there was chemical interaction between NO and hydrogencontaining oxygen atom of BA,and the easily deprotonated nature of BA facilitates the absorption of NO.