Low supported nickel-cobalt catalyst for hydrogenation of maleic anhydride

In order to prepare supported catalysts with low-metal loading, a series of NiCo/Clay catalysts were prepared and used in the hydrogenation of maleic anhydride. The hydrogenation reaction was carried out in a fixed-bed for 8 h with reaction pressure = 1 MPa, reaction temperature = 180 °C, molar ratio of H2: maleic anhydride = 50, WHSV = 2 h−1. Ni4Co1/Clay (loaded 3 wt%Ni and 0.75 wt%Co) can maintain no obvious catalyst deactivation within 8 h. The overall conversion of maleic anhydride is not less than 95 %, and the selectivity of succinic anhydride is up to 100 %. N2 adsorption–desorption characterization, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption, X-ray photoelectron spectroscopy and transmission electron microscopy were performed to verify the changes in catalyst morphology, active species, reduction performance and hydrogenation activity after adding Co as a promoter. With the addition of Co additive, the distribution of active sites on the carrier is more uniform, the grain size of active metal becomes smaller and the reduction temperature decreases. The addition of Co not only increased the active center of the catalyst but also effectively avoided the catalyst's deactivation.