Palladium Nanoparticles Supported On Nanosheet-Like Graphitic Carbon Nitride For Catalytic Transfer Hydrogenation Reaction

In this study, palladium nanoparticles supported on bulk and nanosheet-like graphitic carbon nitride (Pd/b-CN and Pd/ns-CN) were prepared and studied for the catalytic transfer hydrogenation (CTH) of furfuryl alcohol (FOL) into tetrahydrofurfuryl alcohol (THFOL) with formic acid (HCOOH) as a hydrogen donor. Sorption experiments show that Pd/ns-CN possesses a higher specific surface area, more surface basic sites, and a higher Pd dispersion as compared to Pd/b-CN. Electronic and optical characterizations suggest that Pd nanoparticles are primarily deposited on the surface sites associated with pyridinic nitrogen atoms, forming an interfacial Mott-Schottky heterojunction that enables electron transfer from the CN support to the Pd nanoparticles. Catalytic testing indicates that as compared to Pd/b-CN, Pd/ns-CN displays a higher turnover frequency (TOF) for THFOL production. According to the experimental observations, we have proposed a catalysis mechanism, in which surface basic sites in abundance and Pd nanoparticles enriched with electrons are believed to be crucial to activate HCOOH (through the cleavages of O-H and C-H bonds) to transfer hydrogen to the C = C bonds in the furan ring of FOL to yield THFOL.