CuZnAlOOH catalysts with Cu0/Cu+ constructed by two-step hydrolysis for ethanol production from syngas

• Published in: Fuel (Guildford) 2022-08, Vol.322, p.124111, Article 124111
• Main Authors: Gu, Yinting, Han, Chun, Huang, Jinhua, Vinokurov, Vladimir A., Huang, Wei
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; CO hydrogenation; Copper zinc gel; Copper znic aluminum oxide hydroxide catalyst; Embedding; Ethanol; Ethanol synthesis; Flakes; Hydrogenation; Hydrolysis; Intermediates; Synthesis gas; Two-step hydrolysis
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2022.124111

[Display omitted] •adjustable Cu0/Cu+ ratio was successfully constructed by two-step hydrolysis.•Cu0/Cu+ ratio can be adjusted by changing relative amount of CuZn gel/solution.•Cu0/(Cu0 + Cu+) ratio has a good corresponding relationship with ethanol production.•the catalyst morphology influences the production of by-products. In this study, a CuZnAlOOH catalyst with adjustable Cu0/Cu+ ratios is successfully prepared by two-step hydrolysis, affording two catalysts with different morphologies. By embedding Cu0 grains on an oxide flake, a typical hydrogen spillover structure is formed, which is favorable for the hydrogenation of intermediates, with the production of a high number of hydrocarbons. On the other hand, by wrapping Cu0 grains in an oxide, hydrogenation is inhibited, and γ-AlOOH and Cu/γ-AlOOH sites are exposed. Ethanol synthesis over the two sites is different from that over the active sites of Cu0 grains embedded on a flake oxide. An approximate linear relationship exists between the mole ratio of CuZngel/(CuZnsolution + CuZngel) and that of surface Cu0/(Cu0 + Cu+). At CuZn gel/(solution + gel) ratios of 1/2–1/3, corresponding to the Cu0/(Cu0 + Cu+) ratios of 0.277–0.358, ethanol is produced in most advantage, the distribution of which is up to 55.5%.