Ning Ping, Song Xin, Li Kai, Wang Chi, Tang Lihong, Sun Xin
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, PR China.
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650500, PR China.
Sci Rep. 2017 Oct 31;7(1):14452. doi: 10.1038/s41598-017-14925-5.
The competitive adsorption and reaction mechanism for the catalytic hydrolysis of carbonyl sulphide (COS) and carbon disulphide (CS) over FeO cluster was investigated. Compared with experimental results, the theoretical study was used to further investigate the competitive adsorption and effect of HS in the hydrolysis reaction of COS and CS. Experimental results showed that FeO cluster enhanced the catalytic hydrolysis effect. Meanwhile, HS was not conducive to the hydrolysis of COS and CS. Theoretical calculations indicated that the order of competitive adsorption on FeO is as follows: HO (strong) >CS (medium) >COS (weak). In the hydrolysis process, the C=S bond cleavage occurs easier than C=O bond cleavage. The hydrolysis reaction is initiated via the migration of an H-atom, which triggers C=S bond cleavage and S-H bond formation. Additionally, we find the first step of CS hydrolysis to be rate limiting. The presence of HS increases the reaction energy barrier, which is not favourable for COS hydrolysis. FeO can greatly decrease the maximum energy barrier, which decreases the minimum energy required for hydrolysis, making it relatively facile to occur. In general, the theoretical results were consistent with experimental results, which proved that the theoretical study was reliable.
研究了FeO团簇上羰基硫（COS）和二硫化碳（CS₂）催化水解的竞争吸附和反应机理。与实验结果相比，利用理论研究进一步考察了HS在COS和CS₂水解反应中的竞争吸附及作用。实验结果表明，FeO团簇增强了催化水解效果。同时，HS不利于COS和CS₂的水解。理论计算表明，在FeO上竞争吸附的顺序为：HO（强）＞CS₂（中等）＞COS（弱）。在水解过程中，C=S键的断裂比C=O键的断裂更容易发生。水解反应通过H原子的迁移引发，从而触发C=S键的断裂和S-H键的形成。此外，我们发现CS₂水解的第一步是速率限制步骤。HS的存在增加了反应能垒，这对COS水解不利。FeO可以大大降低最大能垒，从而降低水解所需的最小能量，使其更容易发生。总体而言，理论结果与实验结果一致，证明了理论研究的可靠性。
