Glycerol-made ultrasmall platinum nanoparticles dispersed on eggshell-derived hydroxyapatite as a stable and superior reduction catalyst

• Glycerol-induced synthesis of ultrasmall PtNPs dispersed on HAP • Adapting a green chemistry point of view: using eggshell-derived HAP as a biocompatible support and glycerol as a green multitask reagent • PtNPs/HAP as a stable and superior catalyst for the hydrogenation of methyl orange • Kinetic and thermodynamic studies corroborated the corresponding reaction mechanism In search of eco-friendly and biocompatible catalytic materials, the present work discovered the facile and efficient polyol synthesis of ultrasmall platinum nanoparticles dispersed on eggshell-derived hydroxyapatite (PtNPs/HAP) using glycerol as a non-toxic solvent, stabilizing and reducing agents. The structural characteristics of PtNPs/HAP were analyzed using various techniques such as XRD, FT-IR, EDX, and HR-TEM. PtNPs were ultrasmall with an average diameter of 2.5 nm and spherical in shape, well-dispersed on the HAP surface with 1 wt% Pt content. The catalytic activity of PtNPs/HAP was evaluated in the hydrogenation of methyl orange (MO) using NaBH 4 as a hydrogen source. The reaction followed first-order kinetic model with an apparent rate constant of 0.5880 min − ¹ at room temperature. Furthermore, PtNPs/HAP demonstrated strong catalytic stability in the reduction, performing effectively for at least five sequential cycles without significant loss of efficiency. The kinetic and thermodynamic studies corroborated the corresponding reaction mechanism, permitting determining the rate-limiting step.