Density functional theory-guided design of oxygen-doped boron nitride stabilized Pd nanoclusters for efficient and recyclable heck coupling reactions

Abstract

The sustainable application of heterogeneous palladium (Pd) catalysts in Heck coupling is hindered by nanoparticle (NPs) aggregation and leaching. Herein, we propose a strategy of rationally designing the local coordination environment of the support to precisely anchor Pd species. Through systematic computational screening of various doped configurations (C/O doping with different sites and concentrations), we discovered that constructing a BO3 local structure in hexagonal boron nitride optimally modulates the charge environment of adjacent boron sites, thereby creating strong anchoring sites for Pd NPs. This significantly enhances metal-support interaction (MSI) and effectively suppresses Pd migration and aggregation. Guided by this theoretical prediction, we successfully synthesized a BNO-700-Air support enriched with local BO3 local structures via controlled thermal calculation and air oxidation. The resulting Pd catalyst achieves ultrahigh dispersion of Pd NPs with an average size of 2.66 nm. In the Heck reaction of iodobenzene and methyl acrylate, it achieves 90 % conversion within 90 min and a low activation energy of 76.03 kJ/mol, outperforming all other examined samples. Moreover, the catalyst maintains stable activity over 10 consecutive cycles, as the BO3-rich environment stabilizes Pd NPs against initial aggregation and provides dynamic anchoring during "leaching-redeposition" process, thereby sustaining high dispersion throughout the cycling process. Substrate scope experiments further demonstrate its broad applicability. This study provides important theoretical and experimental foundations for designing highly active and stable Heck reaction catalysts.

Keywords: DFT-guided catalyst design; Heck coupling recyclability; Oxygen-doped boron nitride; Palladium nanocluster stabilization; Strong metal-support interaction.