Valencia Diego, Díaz-García Leonardo, Ramírez-Verduzco Luis Felipe, Qamar Amir, Moewes Alexander, Aburto Jorge
Dirección de Investigación en Transformación de Hidrocarburos, Instituto Mexicano Del Petróleo Eje Central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan CP 07730 Mexico City Mexico
Department of Physics and Engineering Physics, University of Saskatchewan 116 Science Place Saskatoon SK S7N 5E2 Canada.
RSC Adv. 2019 Jun 11;9(32):18292-18301. doi: 10.1039/c9ra03208h. eCollection 2019 Jun 10.
A series of Mo-based catalysts were synthesized by tuning the sulfidation temperature to produce mixtures of MoO and MoS as active phases for the hydrodeoxygenation (HDO) of palmitic acid. Differences in the oxidation states of Mo, and the chemical species present in the catalytic materials were determined by spectroscopic techniques. Palmitic acid was used as a fatty-acid model compound to test the performance of these catalysts. The catalytic performance was related to different chemical species formed within the materials. Sulfidation of these otherwise inactive catalysts significantly increased their performance. The catalytic activity remains optimal between the sulfidation temperatures of 100 °C and 200 °C, whereas the most active catalyst was obtained at 200 °C. The catalytic performance decreased significantly at 400 °C due to a higher proportion of sulfides formed in the materials. Furthermore, the relative proportion of MoO to MoS is essential to form highly active materials to produce O-free hydrocarbons from biomass feedstock. The transition from MoS to MoO reveals the importance of Mo-S and Mo-O catalytically active species needed for the HDO process and hence for biomass transformation. We conclude that transitioning from MoS to MoO catalysts is a step in the right direction to produce green fuels.
通过调节硫化温度合成了一系列钼基催化剂，以制备氧化钼（MoO）和硫化钼（MoS）的混合物作为棕榈酸加氢脱氧（HDO）的活性相。通过光谱技术确定了钼的氧化态以及催化材料中存在的化学物种的差异。棕榈酸用作脂肪酸模型化合物来测试这些催化剂的性能。催化性能与材料中形成的不同化学物种有关。这些原本无活性的催化剂的硫化显著提高了它们的性能。催化活性在100℃至200℃的硫化温度之间保持最佳，而在200℃时获得了活性最高的催化剂。由于材料中形成的硫化物比例较高，在400℃时催化性能显著下降。此外，MoO与MoS的相对比例对于形成高活性材料以从生物质原料生产无氧烃至关重要。从MoS到MoO的转变揭示了HDO过程以及生物质转化所需的Mo-S和Mo-O催化活性物种的重要性。我们得出结论，从MoS催化剂转变为MoO催化剂是生产绿色燃料的正确方向上的一步。
