Iodide-Coordinated Single-Site Pd Catalysts for Alkyne Dialkoxycarbonylation

Heterogeneous single-metal-site catalysts (HSMSCs) have attracted considerable interest, but most studies focused on the metal atoms in active site while ignoring key role of ligands. The unique coordination environment a single-site catalyst is crucial for realizing its potential. Constructing this kind via feasible and practical fabrication method challenging. Herein, Pd with iodide ligands supported activated carbon (Pd1/AC) was successfully fabricated by atomic dispersion large nanoparticles (NPs). Intermediate I• radicals were detected during process NPs situ imaging photoelectron photoion coincidence spectroscopy (in iPEPICO) vacuum ultraviolet synchrotron radiation. molecular structure established as [Pd(CO)I4(O?AC)]2– through combined characterization. Alkyne dialkoxycarbonylation high selectivity toward 1,4-dicarboxylic acid esters (>94%) acetylene conversion (>99%) achieved. A sulfonic promoter Pd1/AC alkyne avoided because ligand. Good durability broad substrate scope