Promoting Effect of Ni(OH)₂ on Palladium Nanocrystals Leads to Greatly Improved Operation Durability for Electrocatalytic Ethanol Oxidation in Alkaline Solution

Abstract

Most electrocatalysts for the ethanol oxidation reaction suffer from extremely limited operational durability and poor selectivity toward the CC bond cleavage. In spite of tremendous efforts over the past several decades, little progress has been made in this regard. This study reports the remarkable promoting effect of Ni(OH) on Pd nanocrystals for electrocatalytic ethanol oxidation reaction in alkaline solution. A hybrid electrocatalyst consisting of intimately mixed nanosized Pd particles, defective Ni(OH) nanoflakes, and a graphene support is prepared via a two-step solution method. The optimal product exhibits a high mass-specific peak current of >1500 mA mg , and excellent operational durability forms both cycling and chronoamperometric measurements in alkaline solution. Most impressively, this hybrid catalyst retains a mass-specific current of 440 mA mg even after 20 000 s of chronoamperometric testing, and its original activity can be regenerated via simple cyclic voltammetry cycles in clean KOH. This great catalyst durability is understood based on both CO stripping and in situ attenuated total reflection infrared experiments suggesting that the presence of Ni(OH) alleviates the poisoning of Pd nanocrystals by carbonaceous intermediates. The incorporation of Ni(OH) also markedly shifts the reaction selectivity from the originally predominant C2 pathway toward the more desirable C1 pathway, even at room temperature.

Ultrathin‐Carbon‐Layer‐Protected PtCu Nanoparticles Encapsulated in Carbon Capsules: A Structure Engineering of the Anode Electrocatalyst for Direct Formic Acid Fuel Cells

“…The chronoamperometric ( i–t ) curves of three electrocatalysts were compared at a constant potential of 0.5 V (vs RHE). Chronoamperometric curves can stringently reflect the deactivation of electrocatalyst under continuous working environment . As seen in Figure c, PtCu/C and Pt/C exhibited sharp activity decay and lost over 80% of their initial activity within 2000 s, which are well consistent with the results of previous Pt‐based FAOR electrocatalysts.…”

A Comprehensive Review on Controlling Surface Composition of Pt‐Based Bimetallic Electrocatalysts

“…[129][130][131] The DFAFC has drawn much attention due to the fact that formic acid processes several significant advantages, such as lower crossover through Nafion membranes and less toxicity. [129][130][131] The DFAFC has drawn much attention due to the fact that formic acid processes several significant advantages, such as lower crossover through Nafion membranes and less toxicity.…”

Porous Trimetallic PtRhCu Cubic Nanoboxes for Ethanol Electrooxidation

“…[12,13] Thus, improving the ability of electrocatalysts for splitting CC bond is critical for the development and application of DEFCs. [10,17] Recently, alloying Pt with other metal is generally considered as an efficient strategy for decreasing the cost of electrocatalyst and simultaneously improving electrocatalytic activity for the EOR. However, expensive price and weak ability of splitting CC bond seriously hamper its commercial applications.…”

“…However, expensive price and weak ability of splitting CC bond seriously hamper its commercial applications. [17,22,23] Considering that CC bond cleavage and CO poisoning, trimetallic Pt-based electrocatalysts have been designed to simultaneously improve their CC bond cleavage capability and antipoisoning capability. [18][19][20][21] For example, the addition of Ru and Rh elements can obviously promote the CC bond cleavage, which is beneficial to the C 1 reaction pathway of the EOR.…”