Highly effective bi‐functional electrochemical activity of Ag ₂ O‐PrO ₂ / γ‐Al ₂ O ₃ electrocatalysts towards OER and ORR

Abstract

The oxygen reduction and evolution reaction (ORR/OER), are the keystones for many energy generating and storage devices, have influence with many electrocatalytic reactions. The sluggish kinetics of these reaction is a challenging situation on the surface of electrodes which imposes large over-potential and affects the energy output of fuel cells. Although the platinum-based electrode materials have excellent activity toward ORR/OER but their high cost limits commercialization of fuel cells. To deal with this problem, platinum-free electrode materials has aroused the considerations of scientists. The present work is proposed to study the oxygen reduction reaction and water oxidation on the surface of xAg 2 O-yPrO 2 /γ-Al 2 O 3 /Glassy-Carbon. The ORR was studied electrochemically via cyclic voltammetry on the surface of these nano-catalysts while the OER was investigated via cyclic voltammetry and linear sweep voltammetry in alkaline media. The mechanism of ORR on catalysts surface was enquired and the results indicate that ORR followed two electrons pathway in case of 10PrO 2 /γ-Al 2 O 3 / Glassy-Carbon while four electrons reduction pathway is identified on surface of others catalysts which divulged that addition of silver with praseodymium shifted the mechanism from 2e À to 4e À pathway. The electrocatalysts featured the stability during multiple scans and no corrosion of electrode in OER/ORR is observed.Different kinetic parameters for both reactions are determined which affirmed that both ORR and OER on the active surface of catalysts is irreversible and diffusion controlled. 4Ag 2 O-6PrO 2 /γ-Al 2 O 3 is indicated to be proficient electro-catalyst among other members of the series, having greater value of mass transport and diffusion coefficients. The bi-functionality of all electrocatalysts are verified by their electrochemical responses in alkaline medium. The catalytic reduction of oxygen and oxidation of water by these electro-catalysts imitates their potential as electrode material in batteries and unitized regenerative fuel cells (URFC) technology for energy production as substitute of platinum electrode.

γ-Alumina Supported Copper Oxide Nanostructures Promoted with Ruthenium Oxide (RuO2-CuO/Al2O3) and Palladium Oxide (PdO-CuO/Al2O3): Efficient Electrodes for Heterogeneous Catalysis of Ammonia Electrooxidation

“…less corrosion of the electrodes and insinuation of cheaper and bountiful transition metals as electrocatalysts, that make the fuel cells more reasonable. 18,19 In first step, dissociation of ammonia occurs. Ammonia dissociates into various nitrogenous species followed by discharge of nitrogen and hydrogen.…”

Bio‐inspired Design of Bidirectional Oxygen Reduction and Oxygen Evolution Reaction Molecular Electrocatalysts

“…[5,6] The devel-opment of novel sustainable energy systems, such as fuel cells, metal-air batteries, and electrochemical water splitting systems, has emerged as an essential tool for our future energy infrastructure. [7][8][9][10][11][12] The sluggish kinetics of oxygen activation have been identified as one of the major concerns for developing those systems. [13,14] The world is eagerly looking forward to the utilization of hydrogen as a sustainable fuel or the facile conversion of intermittent renewable energy resources to readily usable energy forms.…”

“…The development of the next generation of energy conversion and storage technologies, which aims to decrease dependence on fossil fuels and minimize carbon emissions, is driven by the rising awareness of low‐carbon economies and sustainable energy generation [5,6] . The development of novel sustainable energy systems, such as fuel cells, metal‐air batteries, and electrochemical water splitting systems, has emerged as an essential tool for our future energy infrastructure [7–12] . The sluggish kinetics of oxygen activation have been identified as one of the major concerns for developing those systems [13,14] .…”

A homogeneous cobalt complex mediated electro and photocatalytic O2/H2O interconversion in neutral water

“… 6 , 7 The metal-air batteries (MAB) and unitized regenerative fuel cell (URFC) setup require the application of both ORR and OER catalysts to operate in their respective charging/discharging and electrolyzer/fuel cell modes. 8 , 9 , 10 , 11 , 12 , 13 Hence, the generation of bidirectional OER/ORR electrocatalysts is reckoned as a pivotal step for small molecule redox-cycle-based renewable energy conversion. 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 The functional modeling of the natural metalloenzymes has emerged as one of the popular choices for replicating the catalytic properties with synthetic model complexes.…”