酸性低共熔溶剂四乙基氯化铵/三氟乙酸高效催化氧化脱除模拟油中的硫化物

将适量四乙基氯化铵（TEAC）和三氟乙酸（TFA）通过简单搅拌加热（70℃）的方式合成一系列新型低共熔溶剂TEAC/nTFA（n=0.5，1，1.5，2），并对其结构进行红外光谱和核磁共振氢谱表征分析。以TEAC/nTFA为催化剂和萃取剂，H₂O₂为氧化剂研究其对模拟油中硫化物的脱除效果。并考察了n_（TEAC（/n_（TFA（、温度、O/S、不同硫化物等反应条件对脱硫效率的影响。在最佳反应条件下，TEAC/TFA对二苯并噻吩（DBT（，苯并噻吩（BT（和噻吩（TH（的脱除率分别达到95.4%，56.2%和23.4%。基于一级动力学和Arrhenius方程，估算出氧化脱除DBT所需的活化能约为56.8 kJ·mol^-1。反应活化能较低，氧化反应较易进行。TEAC/TFA回收利用5次之后活性无明显降低。

Highly efficient catalytic oxidation desulfurization from model oil based on acid deep eutectic solvents tetraethylammonium chloride/trifluoroacetic acid

A series of new deep eutectic solvents (DESs)TEAC/nTFA(n=0.5,1,1.5,2) were synthesized by the reaction of tetraethylammonium chloride (TEAC) with trifluoroacetic acid (TFA) at 70℃ via simple stirring. The structure of the deep eutectic solvents was analyzed by FT-IR and ¹H NMR. The removal of sulfide in model oil was studied by using TEAC/TFA as catalyst and extraction agent, and H₂O₂ as oxidant. The influence of n_(TEAC)/n_(TFA), temperature, O/S and the type of sulfur-containing compound on the desulfurization efficiency were investigated. Under the optimal conditions, the removal rates of dibenzothiophene (DBT), benzothiophene (BT) and thiophene (TH) were 95.4%, 56.2% and 23.4%, respectively. The apparent activation energy was 56.8 kJ·mol^-1 for the removal of DBT, which was estimated by first order reaction kinetics equation and Arrhenius equation. Oxidation reaction was easier to carry out because of the lower apparent activation energy. TEAC/TFA was reused for 5 times without significant decrease in activity.