Mo 2 C/Al 2 O 3 catalyst was prepared by the impregnation method with urotropine and ammonium paramolybdate. The catalytic effect of Mo 2 C as a typical transition-metal carbide in sulfur-resistant methanation was studied. The catalysts prepared were characterized by N 2 adsorption–desorption, X-ray diffraction, transmission electron microscopy, H 2 -temperature-programmed reduction, and Raman spectra, with the results confirming the formation of β-molybdenum carbide on the surface of the catalysts. Studies on catalysts with different loading doses indicate that the optimal loading of Mo 2 C/Al 2 O 3 is about 15 wt.%, which enables CO conversion rate of up to 47%, with methane selectivity of up to 53%. This work further explored the effect of different concentrations of H 2 S in the raw gas on the performance of the catalyst, with the results showing that high concentration of H 2 S (>1500 ppm) can lead to sulfuration of active species on the catalyst, while resulting in a decrease in the catalytic activity.
Yang Zhi,Luo Mingsheng,Liu Qinglong,Li Chenmeng,Wang Yatao,Li Hongjuan,Yao Lifei
Abstract The direct production of higher alcohols from syngas in a single step remains a great challenge. In this work, a series of K and Ni promoted Mo 2 C/Al 2 O 3 catalysts were prepared by impregnation method to enhance the selectivity of Mo 2 C-based catalysts for the one-step conversion of syngas to higher alcohols. The catalysts were continuously tested under the following conditions: 300°C, 3.0 MPa, velocity—11.50 \({\text{Lg}}_{{{\text{Mo}}}}^{{ - 1}}\) h –1 , H 2 /CO ratio of 2. The catalysts promoted with K and Ni demonstrated the highest total alcohol selectivity of 67.7%. Moreover, the selectivity for total C 2+ alcohols reached as high as 56%, with 37% being ethanol. X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS) characterization data reveal that K can promote the crystallinity of β-Mo 2 C, lower the catalyst reduction temperature and increase the proportion of high-valent Mo on the catalyst surface. In addition, adding Ni as a promoter to the KMo 2 C/Al 2 O 3 catalyst can generate a synergistic effect to further enhance the catalytic activity and the selectivity of higher alcohols.
危险品化学品经营许可证（带存储）