Faculty of Chemical Engineering, Petrochemical center of Excellency, Amirkabir University of Technology, Tehran, Iran.
Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, Iran.
Environ Sci Pollut Res Int. 2019 Apr;26(10):9686-9696. doi: 10.1007/s11356-019-04419-4. Epub 2019 Feb 7.
In the present study, a detailed investigation was carried out on MoO alumina-supported catalysts behavior in selective catalytic reduction of SO to sulfur with CH. At first, four different molybdenum catalysts with weight rates of 0, 5, 10, and 15 were impregnated on γ-alumina to be characterized using XRD, SEM, BET, BJH, and N adsorption. Then, to find the most active catalyst, temperature dependency test was performed on all of the prepared catalysts and the result representing Al2O3-Mo10 as the best catalyst. In next step, the effects of feed gas composition, space velocity, and long-term activity, as an important industrial factor, were tested on AlO-Mo10. It was revealed instantaneously from the beginning, MoO specie started to convert mainly into MoS and MoO, and a minor part into MoC, which is terminated after 750 min achieving a stable condition. Thereafter, SO conversion and sulfur selectivity increased from 85.8 to 89.4% and 99.4 to 99.7%, respectively. XRD graph of the used catalyst and TPO thermogravimetric/mass-spectra proved possible happening of the proposed mechanism in long-term activity. At the end, mean activation energy was determined based on Arrhenius model in temperature range of 550 to 800 °C, with a value of 0.33 eV for AlO-Mo10.
在本研究中，对 MoO/氧化铝负载型催化剂在 CH 选择性催化还原 SO 为硫的反应中的行为进行了详细研究。首先，将四种不同的钼催化剂（重量比为 0、5、10 和 15）浸渍在γ-氧化铝上，采用 XRD、SEM、BET、BJH 和 N 吸附进行了表征。然后，为了找到最活性的催化剂，对所有制备的催化剂进行了温度依赖性测试，结果表明 Al2O3-Mo10 为最佳催化剂。在下一步中，考察了进料气组成、空速和长期活性（作为一个重要的工业因素）对 AlO-Mo10 的影响。结果表明，MoO 物种开始主要转化为 MoS 和 MoO，以及少量转化为 MoC，在 750 分钟后达到稳定状态，这一过程在实验开始时就立即发生。此后，SO 转化率和硫选择性分别从 85.8%增加到 89.4%和从 99.4%增加到 99.7%。使用后的催化剂的 XRD 图谱和 TPO 热重/质谱证明了在长期活性中提出的机制的可能发生。最后，根据 Arrhenius 模型，在 550 到 800°C 的温度范围内，确定了 AlO-Mo10 的平均活化能为 0.33 eV。
