Electrochemical Dealloying-Assisted Surface-Engineered Pd-Based Bifunctional Electrocatalyst for Formic Acid Oxidation and Oxygen Reduction

Abstract

Synthesis of non-Pt bifunctional electrocatalyst for the anodic oxidation of liquid fuel and cathodic reduction of oxygen is of great interest in the development of energy conversion devices. We demonstrate a facile room-temperature synthesis of surface-engineered trimetallic alloy nanoelectrocatalyst based on Co, Cu, and Pd by thermodynamically favorable transmetallation reaction and electrochemical dealloying. The quasi-spherical Co x Cu y Pd z trimetallic catalysts were synthesized by the thermodynamically favorable reaction of K 2 PdCl 4 with sheetlike Co m Cu n bimetallic alloy nanostructure. The surface engineering of Co x Cu y Pd z was achieved by electrochemical dealloying. The surface-engineered alloy electrocatalyst exhibits excellent bifunctional activity toward formic acid oxidation reaction (FAOR) and oxygen reduction reaction (ORR) at same pH. The elemental composition and lattice strain control the electrocatalytic performance. The elemental composition-dependent compressive strain weakens the adsorption of oxygen-containing species and favors the facile electron transfer for FAOR and ORR. The engineered alloy electrocatalyst of Co 0.02 Cu 13.8 Pd 86.18 composition is highly durable and delivers high mass-specific activity for ORR and FAOR. It delivers mass-specific activities of 1.50 and 0.202 A/mg Pd for FAOR and ORR, respectively, in acidic pH. The overall performance is superior to that of as-synthesized Pd and dealloyed bimetallic Co 2.7 Pd 97.3 and Cu 5.61 Pd 94.39 nanoelectrocatalysts.

Highly Stable Pt‐Based Ternary Systems for Oxygen Reduction Reaction in Acidic Electrolytes

“…Both chemical and electrochemical leaching have been used to surface-engineer dealloying-driven nanoporous metal alloy electrocatalysts. [84][85][86][87] One advantage of the chemical leaching process is its simplicity. For example, once in contact with acid, less noble metal atoms immediately dissolve out of Pt-based alloys from the near-surface compositions, over time leaving behind a disordered layer of pure Pt several atoms thick.…”

High Active PdSn Binary Alloyed Catalysts Supported on B and N Codoped Graphene for Formic Acid Electro-Oxidation

“…It is generally accepted that the electrooxidation of formic acid follows a dual-pathway mechanism [8,38]. One is a dehydrogenation path which directly produces CO 2 by reaction (2), and the other is a dehydration path which makes CO 2 by multi-step reactions (3)- (5 dual-pathway mechanism [8,38]. One is a dehydrogenation path which directly produces CO2 by reaction (2), and the other is a dehydration path which makes CO2 by multi-step reactions (3−5).…”

“…In order to improve the electrocatalytic activity and reduce the usage of the Pd catalysts, one feasible strategy is to form Pd-based alloys by incorporating non-precious metals. PdCo, PdFe, PdCu, PdNiPdSn and PdBi binary electrocatalysts have shown higher catalytic activities and stabilities for the electro-oxidation of small molecules (e.g., alcohol and formic acid) as well as oxygen reduction reation (ORR), than commercial Pd/C catalysts [5][6][7][8][9][10]. For example, Du et al presented Pd86Sn14 showing much enhanced current densities and durability toward ethanol oxidation reaction among three carbon-supported Pd-Sn catalysts [11], while Adam suggested that Pd 1.5 Sn shows the best electro-catalytic activity [12].…”

Laser-Assisted Synthesis of Pd Aerogel with Compressive Strain for Boosting Formate and Ethanol Electrooxidation

“…Microstrain is defined as a parameter to investigate a crystal “defectiveness” . The classical processes for introducing defects include dealloying, − building special structures, , and rapid annealing. , …”