Catalyzing towards clean energy: tuning the oxygen evolution reaction by amide-functionalized Co(ii) and Ni(ii) pristine coordination polymers

Abstract

We present the synthesis and characterization of two monometallic coordination polymers, [Co(L)₂(H₂O)₂]_n (Co-CP) and [Ni(L)₂(H₂O)₂]_n (Ni-CP), alongside a heterobimetallic counterpart, CoNi-CP, derived from an amide-based multifunctional pro-ligand 4-(pyrimidin-5-ylcarbamoyl)benzoic acid (HL), and discussed their electrocatalytic activity in the oxygen evolution reaction (OER). The CPs were characterized using various techniques, including elemental analysis, IR spectroscopy, X-ray diffraction, and thermal and powder XRD analyses. The low-cost amide-functionalized transition metal pristine coordination polymers Co-CP and Ni-CP were demonstrated to catalyze the OER in alkaline media, surpassing the benchmark IrO₂ electrocatalyst performance. The heterometallic coordination polymer (CoNi-CP) displayed a lower Tafel slope value (and thus, faster kinetics) and higher long-term durability compared to its monometallic counterparts, Co-CP and Ni-CP. The results obtained show a pristine transition metal heterobimetallic coordination polymer as a low-cost electrocatalyst of great promise and high performance for OER catalysis in alkaline media.