Wang Letian, Etim Ubong Jerome, Zhang Chenchen, Amirav Lilac, Zhong Ziyi
Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou 515063, China.
Schulich Faculty of Chemistry, Technion-Israel Institute of Technology (IIT), Haifa 32000, Israel.
Nanomaterials (Basel). 2022 Jul 23;12(15):2527. doi: 10.3390/nano12152527.
CuZnO/AlO is the industrial catalyst used for methanol synthesis from syngas (CO + H) and is also promising for the hydrogenation of CO to methanol. In this work, we synthesized AlO nanorods (n-AlO) and impregnated them with the CuZnO component. The catalysts were evaluated for the hydrogenation of CO to methanol in a fixed-bed reactor. The support and the catalysts were characterized, including via in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The study of the CO adsorption, activation, and hydrogenation using in situ DRIFT spectroscopy revealed the different roles of the catalyst components. CO mainly adsorbed on the n-AlO support, forming carbonate species. Cu was found to facilitate H dissociation and further reacted with the adsorbed carbonates on the n-AlO support, transforming them to formate or additional intermediates. Like the n-AlO support, the ZnO component contributed to improving the CO adsorption, facilitating the formation of more carbonate species on the catalyst surface and enhancing the efficiency of the CO activation and hydrogenation into methanol. The synergistic interaction between Cu and ZnO was found to be essential to increase the space-time yield (STY) of methanol but not to improve the selectivity. The 3% CuZnO/n-AlO displayed improved catalytic performance compared to 3% Cu/n-AlO, reaching a CO conversion rate of 19.8% and methanol STY rate of 1.31 mmolgh at 300 °C. This study provides fundamental and new insights into the distinctive roles of the different components of commercial methanol synthesis catalysts.
CuZnO/Al₂O₃是用于由合成气（CO + H₂）合成甲醇的工业催化剂，在CO加氢制甲醇方面也很有前景。在本工作中，我们合成了Al₂O₃纳米棒（n-Al₂O₃）并将CuZnO组分负载于其上。在固定床反应器中对这些催化剂进行了CO加氢制甲醇的评价。对载体和催化剂进行了表征，包括通过原位漫反射红外傅里叶变换光谱（DRIFTS）进行表征。使用原位DRIFT光谱对CO的吸附、活化和加氢的研究揭示了催化剂各组分的不同作用。CO主要吸附在n-Al₂O₃载体上，形成碳酸盐物种。发现Cu有助于H解离，并进一步与n-Al₂O₃载体上吸附的碳酸盐反应，将它们转化为甲酸盐或其他中间体。与n-Al₂O₃载体一样，ZnO组分有助于改善CO吸附，促进在催化剂表面形成更多的碳酸盐物种，并提高CO活化和加氢生成甲醇的效率。发现Cu和ZnO之间的协同相互作用对于提高甲醇的时空产率（STY）至关重要，但对提高选择性并无帮助。与3% Cu/n-Al₂O₃相比，3% CuZnO/n-Al₂O₃表现出更好的催化性能，在300℃时CO转化率达到19.8%，甲醇STY速率达到1.31 mmol·g⁻¹·h⁻¹。本研究为商业甲醇合成催化剂不同组分的独特作用提供了基础的新见解。
