Synthesis of succinic anhydride from maleic anhydride on Ni/diatomite catalysts

The characteristics and catalytic properties of Ni(5 wt%)/diatomite, Ni(5 wt%)/γ-Al2O3, Ni(5% wt)/Bentonite clay and Ni(5 wt%)/attapulgite clay were investigated and compared in terms of catalytic activities for liquid-phase hydrogenation of maleic anhydride (MA). The results showed that the diatomite support exhibited the highest activity and selectivity. Using Ni(7 wt%)/diatomite catalyst, the 100% conversion of MA and 96.20% selectivity to SA were obtained for MA hydrogenation at 190 °C. The X-ray diffraction (XRD) studies showed that there is only NiO on the support and no elemental nickel (Ni0) and Ni2O3 was detected in unreduced samples. XRD and H2 temperature-programmed reduction (TPR) studies also showed that NiO species were all converted to metallic nickel (Ni0) after reduction at 350 °C.