Electrochemical Oxygen Reduction Reaction Performance of Water Hyacinth Derived Porous Non-precious Electrocatalyst in Alkaline Media

Abstract

This research studied the possibility of converting water hyacinth biomass into the porous non-precious oxygen reduction reaction (ORR) electrocatalyst using a simple, low cost and scalable autogenic pressure method. The electrocatalyst was prepared by thermally annealing water hyacinth root contained ZnCl2 at 700oC under autogenic pressure conditions. The phase of the catalyst was the mixture of carbon and metal oxide. In addition, rough surface morphology and high porosity were clearly observed using scanning electron microscope. The synthesized catalyst was then determined the ORR performance by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) techniques under O2 saturated KOH solution. The ORR performance increased as the catalyst loading was increased and the optimum catalyst loading was found to be 1.5 mg/cm2 which generated the Eonset and E1/2 value of 0.93 V and 0.80 V vs. RHE, respectively. Furthermore, the E1/2 value of the synthesized catalyst was 230 and 130 mV greater than the catalyst synthesized without ZnCl2 and commercial carbon (VXC-72R). ORR durability study suggested that the prepared catalyst was durable to operate ORR for 5000 cycles in alkaline media. These results suggested that the autogenic pressure conditions would be a promising technique to prepare highly active and durable biomass derived ORR electrocatalyst.

N and S Dual-Doped Mesoporous Carbon Nanostructure as a High Performance and Durable Metal Free Oxygen Reduction Reaction Electrocatalyst

“…The reference Ag/AgCl potential was converted to the reversible hydrogen electrode (RHE) potential following the equation reported in the literature [19]. The catalyst ink with the composition of 5 mg catalyst, 250 μL of DI-water, 20 μL of Nafion (5%), and 500 μL of isopropyl alcohol was ultrasonically dispersed for 30 min to obtain a homogenous ink [20][21][22]. The homogeneous ink was then carefully coated onto a clean RRDE electrode and left it dry under room temperature.…”