Liu Yiliang, Wu Peng, Shen Kai, Zhang Yaping, Li Guobo, Li Bo
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China.
Jiangsu Langrun Environment Protection Sci & Tech Co., Ltd., Wuxi, Jiangsu 214000, China.
ACS Omega. 2022 Apr 6;7(15):13299-13312. doi: 10.1021/acsomega.2c00968. eCollection 2022 Apr 19.
As an organic sulfur pollutant generated in blast furnace gas, carbonyl sulfide (COS) has attracted more attention due to its negative effects on the environment and economy. The TiO-AlO composite metal oxide (TiAl) with uniformly dispersed particles was prepared by the co-precipitation method. And on this basis, a series of Na/K-doped catalysts were prepared separately. The activity evaluation results showed that the introduction of Na/K significantly improved the low-temperature COS hydrolysis activity, which exhibited a COS conversion of 98% and HS yield of 95% at 75 °C with 24,000 h. And K showed a better promoting effect than Na. Brunauer-Emmett-Teller (BET) results revealed the increased mesopore proportion of Na/K-modified catalysts. X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that Na and K formed prismatic and nanorod-like structures, respectively. More weakly basic sites with enhanced intensity and decreased O/O content contributed to the excellent catalytic activity, as certified by the results of CO temperature-programmed desorption (CO-TPD) and X-ray photoelectron spectroscopy (XPS). It was also proposed that the decrease of weakly basic sites ultimately deactivated catalyst activity. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed that the introduction of Na/K enhanced the dissociation of HO, and the generated abundant hydroxyl groups promoted the adsorption of COS and formed surface transition species, such as HSCO and HCO .
作为高炉煤气中产生的一种有机硫污染物，羰基硫（COS）因其对环境和经济的负面影响而受到更多关注。采用共沉淀法制备了颗粒均匀分散的TiO-AlO复合金属氧化物（TiAl）。在此基础上，分别制备了一系列Na/K掺杂催化剂。活性评价结果表明，Na/K的引入显著提高了低温COS水解活性，在75℃、24000 h的条件下，COS转化率达到98%，H₂S产率达到95%。并且K的促进效果优于Na。Brunauer-Emmett-Teller（BET）结果表明，Na/K改性催化剂的中孔比例增加。X射线衍射（XRD）和扫描电子显微镜（SEM）表明，Na和K分别形成了棱柱形和纳米棒状结构。CO程序升温脱附（CO-TPD）和X射线光电子能谱（XPS）结果证明，更多强度增强且O²⁻/O⁻含量降低的弱碱性位点有助于优异的催化活性。还提出弱碱性位点的减少最终会使催化剂失活。原位漫反射红外傅里叶变换光谱（DRIFTS）表明，Na/K的引入增强了H₂O的解离，生成的大量羟基促进了COS的吸附并形成了表面过渡物种，如HSCO⁻和HCOO⁻。
