Synthesis and Properties of Organotrialkoxysilane Functionalized Palladium–Cobalt Heterogeneous Catalysts for Oxygen Evolution Reaction

Abstract

Abstract: Despite the widespread use of noble metal nanocatalysts in heterogeneous catalysis, their catalytic efficiency per-noble metal atom is still inadequate. Organotrialkoxysilane mediated formation of Co@Pdnps were made using Co–NTA nanowires as a precursor. Co@Pdnps were synthesized using variable content of organotrialkoxysilane in an N-doped carbon matrix (Co@Pdnps) to control the presence of nanostructured silica after calcination useful in OER and analyzed by XRD, TEM, SEM, XPS, and EDX. Three systems of bimetallic nanocatalysts of composition after calcination: (i) Co@Pdnps1: Si = 4.54%; Pd = 4.36% and Co = 91.10%; (ii) Co@Pdnps2: Si = 2.81%; Pd = 5.83% and Co = 91.36% and (iii) Co@Pdnps3: Si = 0.00, Pd = 9.48, Co = 90.52 are made justifying the impact of nanostructured silica and palladium nano geometry on OER. The presence of nanostructured silica facilitates (a) re-cyclability of nanocatalyst, (ii) significantly improves the palladium nano geometry, (iii) effective interaction of cobalt and palladium components during OER. A nanostructured silica-derived thin film composed of Co@Pdnps produced a very high current density at a low overpotential with a minor Tafel slope of 39 mV dec–1 and a catalyst loading of 3.5 mg cm–2 on the carbon cloth. In the absence of silica, the nanocatalysts are relatively larger with comparatively less current density(19 mA cm–2) as compared to (20.5 mA cm–2) recorded with high silica content. © 2023, Pleiades Publishing, Ltd.