炔醛化反应中pH值对铜基催化剂催化性能影响的研究

Effect of pH value on catalytic performance of copper-based catalysts in reaction of acetylene with formaldehyde

炔醛化反应通常采用铜基催化剂,pH值对反应有较大影响,控制反应过程中pH值在6~7范围内,1,4-丁炔二醇收率与选择性最佳。通过SEM、N2吸附-脱附、XRD和FT-IR对反应前后的碱式碳酸铜催化剂进行表征,研究pH值对催化剂催化性能的影响。结果发现反应过程中pH值较低,会造成催化剂形貌与织构性质发生改变,导致活性物质乙炔亚铜降低,促进线型碳(尤其是β型线型碳)增加,不利于催化反应的进行。同时,研究还发现了炔醛化反应中间物CuC≡CCH2OH的存在。

The yield and selectivity of 1, 4-butanediol are the best when the pH value is controlled in the range of 6-7 in the reaction process of acetylene with formaldehyde catalyzed by copper catalyst. The basic copper carbonate catalyst before and after the reaction was characterized by SEM, N2 adsorption-desorption, XRD and FT-IR. The results showed that the lower pH value in the reaction process would change the morphology and texture of the catalyst, lead to the decrease of the active substance cuprous acetylide, and promote the increase of linear carbon(especially beta-type linear carbon), which is unfavorable to the catalytic reaction. At the same time, CuC≡CCH2OH, the intermediate of acetylene-formaldehyde reaction, was also found.