Strong metal-support interaction of palladium carbide in PtPd/C catalysts for enhanced catalytic transfer hydrogenolysis of glycerol

Abstract

Catalytic transfer hydrogenolysis of glycerol can give 1,2-propanediol under mild condition (200 °C) in the absence of external H2. Most existing studies have been focused on metallic catalysts for tandem H2 generation and hydrogenolysis. In this work, a series of bimetallic PtPd/C catalysts with PdCx as promoting role, were synthesized with different calcination temperatures (300–900 °C) and varied Pt/Pd molar ratio (Pd/Pt: 0.5–2.0), to investigate the structure-activity relationship over the in-situ transfer hydrogenation of glycerol. In particular, PtPd/C-900 catalysts showed the best performance (TOF: 37.6 h−1, 1,2-PDO selectivity: 45.3%). It is evidenced that varied metal particle sizes (2.6–7.0 nm) were obtained, and catalytic transfer hydrogenolysis of glycerol displayed size sensitivity over PtPd/C catalysts. Besides, strong metal-support interaction can promote the formation of palladium carbide (PdCx), thus changing the electronic structure of Pt atoms, and improving the activity of hydrogenation reaction and WGS + Reforming reaction. This study will provide insights for the structural design of catalyst for selective transfer hydrogenation of bio-polyols.