Bifunctional Behavior of Pd/Ni Nanocatalysts on MOF‐Derived Carbons for Alkaline Water‐splitting

Abstract

Metal-organic framework derived carbon (MOFDC) serves as supporting platforms for PdNi catalyst (Pd/Ni/MOFDC) and acid-treated nickel counterpart (Pd/AT-Ni/MOFDC). The two Pd-based electrocatalysts are tested for alkaline water-splitting (i. e., hydrogen evolution (HER) and oxygen evolution reactions (OER)). The results reveal better HER and OER kinetics for Pd/Ni/MOFDC than Pd/AT-Ni/MOFDC. DFT calculations show that the high performance of the Pd/Ni/MOFDC can be associated with its high conductivity toward adsorbed OH compared to the Pd/AT-Ni/ MOFDC counterpart. The superior overall water-splitting of Pd/Ni/MOFDC describes the synergy between Ni/Ni (OH) 2 interface and nanostructured Pd for possible future application in an electrolyzer.

Porous spinel-type transition metal oxide nanostructures as emergent electrocatalysts for oxygen reduction reactions

“…This is also achievable using other supports, like metal–organic frameworks (MOF), carbon nitride, MXenes, carboxylated carbon/graphene, and graphdiyne, owing to their rich electron density, unique physicochemical properties, and catalytic/photocatalytic merits. 2,154–164…”

“…This is also achievable using other supports, like metal-organic frameworks (MOF), carbon nitride, MXenes, carboxylated carbon/graphene, and graphdiyne, owing to their rich electron density, unique physicochemical properties, and catalytic/photocatalytic merits. 2,[154][155][156][157][158][159][160][161][162][163][164] ➢ 3D porous PS-TMO nanocatalysts (i.e., branched, dendrites, and yolk-shell) can accelerate ion diffusion and active catalytic sites and maximize the utilization of elements during ORR.…”

Efforts at Enhancing Bifunctional Electrocatalysis and Related Events for Rechargeable Zinc‐Air Batteries

“…Alkaline Electrolytes: Conventional RZAB utilizes aqueous alkaline electrolytes where both the Zn anode and air electrocatalysts are at their best conditions because it endears the following properties: [123][124][125] (i) electrochemical reversibility and fast kinetics of the Zn anode and air electrocatalysts for the ORR and OER; (ii) high ionic conductivity; (iii) relatively good performance at ambient temperature; (iv) high solubility of Zn salts; and (v) possibility of using non-Pt, economically effective and durable positive electrodes. Thus, the most commonly used electrolytes in RZABs are alkaline aqueous solutions containing potassium hydroxide (KOH), [121] sodium hydroxide (NaOH), [126] and lithium hydroxide (LiOH).…”

“…In alkaline RZABs, shape changes occur when Zn particles migrate owing to the gravitational pull from the top and side to the bottom. [125] The redistribution of active materials causes an irreversible loss of capacity and triggers the formation of dendrites, which can puncture the separators leading to an internal short circuit. [125] Zn anode's shape change and dendrite formation can be mitigated by adding compounds that suppress Zn dissolution in alkaline media.…”

“…[125] The redistribution of active materials causes an irreversible loss of capacity and triggers the formation of dendrites, which can puncture the separators leading to an internal short circuit. [125] Zn anode's shape change and dendrite formation can be mitigated by adding compounds that suppress Zn dissolution in alkaline media. [152] The additives can form insoluble complexes with Zn and cause a reduction in the electrolyte's pH.…”