Mesoporous Nickel/Nickel Hydroxide Catalyst Using Liquid Crystal Template for Ethanol Oxidation in Alkaline Solution

Abstract

A mesoporous nickel/nickel hydroxide (Ni/Ni(OH) 2 ) catalyst was prepared by chemical reduction of nickel ions dissolved in the interstitial spaces of the hexagonal liquid crystalline template of the non-ionic surfactant Brij56. The physicochemical characterizations of the catalyst performed by surface area analyzer, X-ray diffraction, scanning and transmission electron microscopes suggests formation of a mesoporous crystalline structure of Ni/Ni(OH) 2 with a surface area of 90 ± 3 m 2 /g. This is an order of magnitude higher than that for nickel particles formed without surfactant template. The electrochemical behavior and ethanol oxidation catalytic activity of the mesoporous Ni/Ni(OH) 2 catalyst was investigated by cyclic voltammetry and chronoamperometry techniques in alkaline medium. The activity of the mesoporous Ni/Ni(OH) 2 catalyst shows a more than 10-fold increase compared to bulk nickel catalyst (formed without surfactant) consistent with the enhancement of electro-active surface area. Bulk liquid-crystal template deposition offers a reproducible platform to fabricate mesoporous metal/oxides/hydroxides with enhanced electrocatalytic performance.

Electrooxidation of Urea in Alkaline Solution Using Nickel Hydroxide Activated Carbon Paper Electrodeposited from DMSO Solution

“…In contrast, the FESEM image in Figure 2c,d reveals that the Ni(OH) 2 electrodeposited from the DMSO (Ni(OH) 2 -DMSO/CP) resembles the morphology of a nanoparticle of CP substrate with the absence of the dense deposit that blocked the interstitial mesopore network, as in case of Ni(OH) 2 -DW catalysts. These Ni(OH) 2 particles over CP prepared from the DMSO solvent tend to have a superior specific surface area to an aqueous solution, and are anticipated to deliver more reactive sites for electrocatalytic reactions [60][61][62]. All the obtained diffraction peaks are indexed to the CP substrate.…”

Effective ionic-liquid microemulsion based electrodeposition of mesoporous Co–Pt films for methanol oxidation catalysis in alkaline media

“…The micellar solutions were prepared by stirring the corresponding aqueous solution for each composition with a non-ionic surfactant (Brij 58) in a 99/1 % ratio (Table 1) [36][37][38][39].…”

Foam Synthesis of Nickel/Nickel (II) Hydroxide Nanoflakes Using Double Templates of Surfactant Liquid Crystal and Hydrogen Bubbles: A High-Performance Catalyst for Methanol Electrooxidation in Alkaline Solution

“…Engineering the electrocatalyst architectures, particularly for nickel-based materials at the nanometer scale, shape, facets, and composition, significantly boosts catalytic activity for the oxidation of small organic molecules [ 4 , 11 , 12 ]. For instance, nickel-based nanostructured electrocatalysts such as Ni/Ni(OH) 2 [ 13 ], Ni(OH) 2 -NiCoO 4 [ 14 ], and NiO MOF/rGO [ 15 ] have gained substantial interest and revealed significant electrocatalytic performance with tolerance to CO poisoning during ethanol [ 16 ] and methanol [ 17 , 18 ] electrooxidations in an alkaline environment.…”

“…Very recently, Ni 3 S 2 enriched with defects and supported on carbon nanofibers (CNFs) showed significant electroactivity and selectivity in the oxidation of methanol to valuable formate with the co-production of hydrogen at an applied potential of 1.37 to 1.62 V vs. RHE and current density of more than 700 mA/cm 2 [ 12 , 22 ]. The Faradic efficiency of the process reached 99%, and the synergistic effect of Ni–OOH and SO x active sites was responsible for selective oxidation of methanol to formate and cathodic hydrogen-intensive production.…”