PtPdCoNiCu/TiO 2 High-Entropy alloy catalyst for synthesis of γ-Butyrolactone by selective hydrogenation of maleic anhydride

The continuous flow selective hydrogenation of maleic anhydride (MA) to gamma -butyrolactone (GBL) over highly efficient and long-term stable catalysts is a considerable promising strategy for both lab-scale as well as industrial application. In this work, a PtPdCoNiCu/TiO 2 high-entropy alloy (HEA) catalyst is developed by the colloidal impregnation method, in which the HEA colloids are synthesized by lithium naphthalenide-driven reduction at mild conditions according to the redox potential of the various metals. The PtPdCoNiCu/TiO 2 catalyst exhibits highly efficient in the hydrogenation of MA with 91 % selectivity to GBL at full conversion of MA under the weighted hourly space velocity of 1.14 h -1 , 3 MPa H 2 , and 260 degrees C. Due to the present of oxygen vacancy in the TiO 2 support and the hydrogen spillover, the PtPdCoNiCu/TiO 2 HEA catalyst presents a low apparent activation energy (75 kJ mol -1 ), boosting the hydrogenolysis of C=O bonds for generating of GBL. The cocktail effect is presented in the PtPdCoNiCu/TiO 2 catalyst, and its catalytic activity is much better than that of corresponding monometallic and bimetallic catalysts. It realizes the reduction and substitution of precious metal catalysts. In addition, the PtPdCoNiCu/TiO 2 catalyst with sintering resistance and acid resistance shows excellent long-term stability within 132 h. This work is of great significance for understanding HEA catalysis at the atomic level and provides the possibility for developing low-cost and efficient precious metal industrial catalysts.