Linear, tripodal, macrocyclic: Ligand geometry and ORR activity of supported Pd(II) complexes

The novel ligand H3L designed to spontaneously adsorb onto MWCNT via electron-deficient pyrimidine residues and bind metal cations is used to prepare an oxygen reduction reaction (ORR) cathode catalyst based on supported Pd(II) complexes. Herein we report the synthesis of the ligand, its solution behaviour (protonation constants, binding constants for the test cation Cu(II), UV evidence of Cu(II) and Pd(II) complexes formation) and ORR performances together with XPS and STEM characterization. Tripodal nature of the H3L ligand frame it in-between previously studied macrocyclic and linear open chain ligands, allowing to draw meaningful comparisons.

Automated summary

The novel ligand H3L designed for spontaneous adsorption onto MWCNT and binding metal cations was used in the preparation of an ORR cathode catalyst based on supported Pd(II) complexes. The synthesis, solution behavior, and ORR performances of the ligand were reported, along with XPS and STEM characterization. The tripodal nature of the H3L ligand places it between macrocyclic and linear open chain ligands, allowing for meaningful comparisons.