Regulating the intermediate affinity on Pd nanoparticles through the control of inserted-B atoms for alkaline hydrogen evolution

Abstract

• The Pd-B/C with the control of inserted-B atoms are synthesized by a facile route. • The optimized Pd-B/C catalyst exhibit superior alkaline HER activity. • The inserted boron atoms is beneficial to regulate the intermediate affinity on Pd. Strong affinity of palladium to hydrogen needs to be overcome in the rational design of highly efficient and robust Pd-based catalyst for hydrogen evolution reaction (HER). In this work, we achieved the insertion of boron atoms in the Pd lattice interstitial sites by a facile co-reduction method, and successfully prepared Pd-B nanoparticles supported on carbon. Benefiting from the optimization of electronic state induced by the control of interstitial boron atoms, the obtained Pd 86 B 14 /C catalyst exhibit pronounced alkaline HER performance with a small overpotential of 38 mV at 10 mA cm −2 and a low Tafel slope of 36.6 mV dec −1 in 1 M KOH. Theoretical calculations unveil that the inserted boron atoms into host palladium leads to the charge redistribution and the lower d-band center on Pd because of the electron transfer between Pd and inserted B. More importantly, the control of inserted boron atoms makes the d-band center of Pd appropriately shift negatively relative to the Fermi level and consequently balances the hydrogen adsorption/desorption behavior of Pd surface, resulting in superior catalytic performance (Pd 86 B 14 /C).