Laser assisted embedding of Pd₁₀Cu bimetals in ZIF-8 enabling highly selective hydrogenation of C = C in π-bond conjugation

Selective hydrogenation of vinyl groups (C = C) and carbonyl groups (C = O) is of significance to effectively convert low-value organic compounds into high-value target chemicals, while a challenge remains on the hydrogenation of C = C bond that is in π-bond conjugation with the C = O bond. Herein, we address this challenge based on a synergetic modulation strategy on electronic structure and adsorption configurations to achieve a highly selective hydrogenation of the C = C bond, achieved by laser-assisted embedding of Pd_xCu bimetals in the ZIF-8 bulk phase (x represents the Pd/Cu molar ratio in PdCu nanoparticles). It is revealed that laser assisted synthesis of Pd_xCu bimetals not only inhibits the hydrogenation of C = O and promotes the hydrogenation of C = C, but also results in an arched absorption configuration for substrate molecules that facilitates the selective hydrogenation of vinyl groups. Exemplified by cinnamaldehyde (CAL), the present work achieves 98.03 % conversion of CAL and 100 % selectivity of the hydrocinnamaldehyde (HCAL) (70 °C, 1 MPa H₂, 1 h), indicating the potential of laser-matter interaction to tackle the trade-off between conversion efficiency and selectivity in thermal catalysis.