Highly Active Sites in Quaternary LnPdAsO (Ln = La, Ce, Pr) with Excellent Catalytic Activity for Hydrogen Evolution Reaction

We report the catalytic activity in LnPdAsO (Ln = La, Ce, Pr). In this PdAs- layer (II), by elongating the distance of Pd-Pd, the overpotentials toward HER are 110.0, 89.5, and 62.0 mV at 10 mA/cm2 for PrPdAsO, CePdAsO, and LaPdAsO, respectively. Furthermore, the Tafel slope and robust long-term stability in LaPdAsO even surpasses the capability of optimized Pd and Pd/C. Density functional theory calculations reveal that the active sites lie at the center of Pd-'s net with a free energy barrier of 0.09 eV for H-H reaction. The present engineering two-dimensional Pd provides a route for exploring superior electrocatalyst on the basis of known noble metals.