Unraveling the origin of Pd nanoparticles supported N–doped biochar derived from spent coffee ground for enhanced Suzuki coupling reaction activity

To convert spent coffee ground into high–value products, a N–doped biochar supported palladium nanoparticles catalyst (Pd NP –NB) was prepared and utilized for the Suzuki coupling reaction. Pd NP –NB with high electron density can efficiently catalyze the Suzuki coupling reaction between iodobenzene and phenylboronic acid , achieving a biphenyl yield of 99.24 % within 12 min. Palladium (Pd) nanoparticles decorated catalyst possesses better catalytic activity compared with its counterparts with palladium oxide nanoparticles or Pd single atoms embedded N–doped biochar (PdO–NB or Pd 1 –NB). Density functional theory calculation and X–ray photoelectron spectroscopy analysis reveal that the high electron density of active sites accelerates the Suzuki coupling reaction. Pd NP –NB has a higher electron density than PdO–NB and Pd 1 –NB, which endows it better catalytic activity. The high electron density of Pd, smaller particle size of nanoparticles and rich porous structure of the materials are proven to be three crucial factors affecting the overall activity. This work not only illustrates the transformation of spent coffee ground into high–value catalyst, solving the issue of domestic waste, but also provides insights for designing new catalysts toward the Suzuki coupling reaction. Pd NP –NB derived from spent coffee ground exhibits splendid catalytic activity toward the Suzuki coupling reaction. The high electron density, smaller particle size of Pd nanoparticles and porous structure are the three crucial factors determining the overall catalytic performance. • Spent coffee ground derived N–doped biochar is employed as support. • N–doped biochar facilitates the dispersion of Pd nanoparticles. • Pd nanoparticles are the most efficient active sites for Suzuki coupling reactions.