Carbon-supported Zn-HPW ligand catalysts for acetylene hydration†

Abstract

In recent years, the production of acetaldehyde with rich raw materials still has high research value. A series of Zn-HPW/AC catalysts with a Zn–O₄ configuration were prepared to solve the problems of easy loss of active components and carbon accumulation of Zn-based catalysts in the reaction. The characterization results showed that the phosphotungstic acid (HPW) ligands effectively promoted Zn species dispersion, provided more acid sites, mitigated the loss of Zn, and improved the carbon deposition resistance of the catalyst. The density functional theory (DFT) calculation further confirmed that the water molecules preferentially adsorb on the surface of the catalyst to promote the dissociation of water molecules, and the H of dissociation from water molecules and Zn forms the most stable Zn–OH configuration, which is the main active center of the reaction. Meanwhile the –OH dissociated from water molecules is adducted with C₂H₂, while H reduces the catalyst, and the original H atoms in the ligand catalyst further participate in the reaction to realize the catalytic cycle. This provides a new idea for the development of green catalysts for acetylene hydration.