当前位置: X-MOL 学术Appl. Catal. B Environ. Energy › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The investigation of the role of basic lanthanum (La) species on the improvement of catalytic activity and stability of HZSM-5 material for eliminating methanethiol-(CH3SH)
Applied Catalysis B: Environment and Energy ( IF 20.2 ) Pub Date : 2018-05-25 , DOI: 10.1016/j.apcatb.2018.05.063
Jichang Lu , Husheng Hao , Liming Zhang , Zhizhi Xu , Liping Zhong , Yutong Zhao , Dedong He , Jiangping Liu , Dingkai Chen , Hongping Pu , Sufang He , Yongming Luo

Lanthanum (La)-doped HZSM-5 and HZSM-5 catalysts were prepared to investigate the natural roles of La addition on the catalytic performance of HZSM-5 for decomposing methanethiol (CH3SH). Compared to HZSM-5, the incorporation of La species into HZSM-5 catalyst not only decreased the intrinsic activation energy (from 51.4 kJ/mol to 40.6 kJ/mol) but also largely improved the stability. Based on the characterizations of X-ray diffraction pattern (XRD), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of carbon dioxide (CO2-TPD), temperature-programmed desorption of ammonia (NH3-TPD), and temperature programmed desorption of CH3SH (CH3SH-TPD), the promotional role of La species on the catalytic activity was demonstrated to be the contribution of the surface active oxygen species within lanthanum oxy-carbonates composites, which not only might act as new active sites for converting CH3SH into CO2 but also could decrease the activation temperature for the dehydrogenation of CH3SH into intermediate, dimethyl sulfide (CH3SCH3). The enhanced stability of La doped HZSM-5 was attributed to the synergistic effect of the decrease in the strong acid sites as well as the formed CO2 and surface lanthanum oxy-carbonates layer. The rapid deactivation of HZSM-5 was due to the formation of deposited coke irrespective of deposited sulfur species. The nature, amount and type of deposited coke were investigated in detail via the characterization of FTIR, Raman spectroscopy, temperature programmed oxidation of oxygen (O2-TPO), thermogravmetric analysis (TGA). A facile and rapid regeneration method was used to regenerate spent La doped HZSM-5 and no significant deactivation was observed even after three cycles of deactivation-regeneration.



中文翻译:

碱性镧(La)物种对改善HZSM-5材料消除甲硫醇-(CH 3 SH)的催化活性和稳定性的作用的研究

制备了镧(La)掺杂的HZSM-5和HZSM-5催化剂,以研究La的添加对HZSM-5分解甲硫醇(CH 3 SH)的催化性能的天然作用。与HZSM-5相比,La物种掺入HZSM-5催化剂不仅降低了固有活化能(从51.4 kJ / mol降至40.6 kJ / mol),而且还大大提高了稳定性。基于X射线衍射图谱(XRD),N 2吸附-解吸,傅立叶变换红外光谱(FTIR),X射线光电子能谱(XPS),温度程序控制的二氧化碳脱附(CO 2 -TPD)的表征,程序升温的氨解吸(NH 3 -TPD)和程序升温的CH脱附在3 SH(CH 3 SH-TPD)中,La物种对催化活性的促进作用被证明是碳氧化镧复合物中表面活性氧的贡献,它不仅可以充当转化的新活性位, CH 3 SH转化为CO 2,但也可以降低将CH 3 SH脱氢为中间体二甲硫(CH 3 SCH 3)的活化温度。La掺杂的HZSM-5的稳定性增强归因于强酸部位减少以及形成的CO 2的协同作用和表面碳酸镧层。HZSM-5的快速失活归因于沉积焦炭的形成,而与沉积的硫物质无关。通过FTIR的表征,拉曼光谱,氧气的程序升温氧化(O 2 -TPO),热重分析(TGA),详细研究了沉积焦炭的性质,数量和类型。一种简便快速的再生方法被用于再生用过的掺La的HZSM-5,即使在三个失活-再生周期后也没有观察到明显的失活。

更新日期:2018-05-25
down
wechat
bug