Effective Performance of the Cu/Zn/SiO<sub>2</sub> Catalyst Applied in the Ethynylation of Formaldehyde for 1,4-Butynediol Synthesis
Guihua Yang, Linxue Yang, Jiali Chen
Abstract
1,4-Butynediol synthesized from the ethynylation reaction of formaldehyde catalyzed by Cu-based catalysts has been of much concern. The stability of a Cu-based catalyst under a reducing atmosphere is still a serious challenge. Herein, a series of Cu/Zn/SiO 2 catalysts were prepared by a deposition precipitation method and applied in the ethynylation of formaldehyde for 1,4-butynediol synthesis. The ethynylation of formaldehyde reaction conditions was optimized, and the activation energy was calculated. Compared with 30Cu/SiO 2, 30Cu15Zn/SiO 2 increases the yield of 1,4-butynediol from 27 to 72% and decreases the reaction activation energy from 28.02 to 15.86 kJ/mol, which improves the catalytic reaction efficiency. The experimental results also show that 30Cu15Zn/SiO 2 and commercial catalysts are well-matched in activity and stability. All catalysts were carefully characterized by different techniques. The results show that ZnO in the Cu/Zn/SiO 2 catalyst plays an important role in dispersing and decreasing the CuO particle size. Moreover, the strong Cu–Zn interaction in the CuO and ZnO interface is beneficial to stabilize the Cu 2 C 2 intermediate, which effectively improves the catalyst performance. Additionally, the appropriate amounts of alkaline sites and oxygen vacancies brought from ZnO are also conducive to activating C 2 H 2 to form Cu 2 C 2 .