Fabrication of Cu-based catalysts for the synthesis of neopentyl glycol from hydroxypivalaldehyde hydrogenation: studies on the role of Zr promoter

In this work, a series of zirconium-modified ternary copper-based catalysts with various loadings were prepared by co-precipitation method, and the promotional roles of zirconium on the selective hydrogenation of hydroxypivalaldehyde (HPA) was evaluated. Zirconium is commonly used as a promoter in Cu-based hydrogenation catalysts, but its promoting mechanism on HPA hydrogenation to neopentyl glycol (NPG) remains ambiguous. Thus, various characterization techniques (e.g. XRD, SEM, FTIR, H₂-TPR, and XPS) have been used to probe the physicochemical properties of zirconium-modified catalysts. The consequences indicate that the incorporation of zirconium will affect the reducibility of the catalyst and the distribution of surface reduced copper and promote the formation of more oxygen vacancies on the catalyst. The catalyst with 5% zirconium loading showed the best catalytic performance probably due to the good synergistic catalytic effect between the oxygen vacancies and the copper species.