Evdokimenko Nikolay, Yermekova Zhanna, Roslyakov Sergey, Tkachenko Olga, Kapustin Gennady, Bindiug Denis, Kustov Alexander, Mukasyan Alexander S
Center of Functional Nano-Ceramics, National University of Science and Technology "MISiS", 119049 Moscow, Russia.
N.D. Zelinsky Institute of Organic Chemistry RAS, 119991 Moscow, Russia.
Materials (Basel). 2022 Jul 23;15(15):5129. doi: 10.3390/ma15155129.
Active and stable catalysts are essential for effective hydrogenation of gaseous CO into valuable chemicals. This work focuses on the structural and catalytic features of single metals, i.e., Co and Ni, as well as bimetallic CoNi alloy catalysts synthesized via combustion of reactive sol-gels. Different characterization methods were used for studying the relationships between the structure, composition, and catalytic activity of the fabricated materials. All catalysts exhibited highly porous sponge-like microstructure. The outermost surfaces of the CoNi alloys were more saturated with Co, while a stoichiometric Co/Ni ratio was observed for the particle's bulk. Catalytic properties of the as-synthesized powders were studied in the CO hydrogenation reaction at 300 °C for over 80 h of time on stream. All the catalysts demonstrated exceptional selectivity with respect to CH formation. However, the combination of elemental Co and Ni in a single phase resulted in a synergistic effect in bulk alloy catalysts, with activity twofold to threefold that of single-metal catalysts. The activity and stability of the CoNi catalyst were higher than those previously reported for Ni-based catalysts. The reasons for this behavior are discussed.
活性和稳定的催化剂对于将气态CO有效氢化为有价值的化学品至关重要。这项工作重点研究了单一金属（即Co和Ni）以及通过活性溶胶 - 凝胶燃烧合成的双金属CoNi合金催化剂的结构和催化特性。使用了不同的表征方法来研究制备材料的结构、组成和催化活性之间的关系。所有催化剂均呈现出高度多孔的海绵状微观结构。CoNi合金的最外表面Co含量更高，而颗粒内部观察到化学计量的Co/Ni比。在300°C的CO加氢反应中对合成粉末的催化性能进行了超过80小时的连续考察。所有催化剂对CH形成均表现出优异的选择性。然而，单相中元素Co和Ni的组合在体相合金催化剂中产生了协同效应，活性是单金属催化剂的两倍至三倍。CoNi催化剂的活性和稳定性高于先前报道的镍基催化剂。讨论了这种行为的原因。
