Efficient C = O bond hydrogenation of cinnamaldehyde over PtCu alloy frame: Insight into the morphology and Pt species state

Highly selective hydrogenation of cinnamaldehyde (CAL) to cinnamic alcohol (COL) remains the great challenge due to the co-existence of C = C and C = O bond in CAL. Herein, Al2O3 supported a series of wheel-like PtCux nanoframes (NFs) with varied Pt/Cu ratios were successfully fabricated, featuring unique electronic and geometric structure. Theoretical calculations and characterizations demonstrate that Cu can effectively optimize the d-band center, improve the distribution and utilization of Pt significantly. Compared with pure Pt crystal, PtCu1.21 NFs display the superior catalytic performance with high selectivity towards COL at a CAL conversion of over 99 %. The in-situ Fourier transform infrared (FTIR) spectroscopy reveals that the highly distribution and optimized d-band center of Pt could effectively weaken C = C bond interaction and strengthen the interaction of C = O bond on catalysts surface, boosting C = O bond hydrogenation to COL.