Theoretical Insights on transition metals confined in black phosphorus for engineering stable single-atom catalysts

Black phosphorus (BP) is a promising support for single-atom catalysts (SACs), yet detailed insights into metal-support interactions remains lacking. Using density functional theory (DFT) and ab initio molecular dynamics (AIMD), we investigate the coordination, electronic properties, and stability of 12 catalytic metals (Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) on BP. Most metals prefer the Hollow site, while Rh and Ir favor substitutional doping. Fe, Co, Ru, and Os exhibit unique embedding within the BP lattice. Covalent bonding is observed between metals and phosphorus atoms, with charge transfer trends aligning with electronegativity: 3d metals are positively charged, 4d metals neutral, and 5d metals negatively charged. Four metals (Ni, Rh, Pd, and Ir) are identified as promising candidates for single-atom dispersion on BP, with stability analysis and AIMD simulations revealing that Ir and Rh exhibit the highest stability, followed by Pd and Ni. Small molecule adsorption studies highlight Rh1/BP as a promising candidate for CO oxidation. These insights provide valuable theoretical guidance for the rational design of BP-supported SACs and understanding their catalytic behavior.