Enhancing the available specific surface area of carbon supports to boost the electroactivity of nanostructured Pt catalysts

Abstract

We report increasing improvements in the available specific surface area of the commonly used Vulcan XC 72R and Ketjenblack EC-600JD carbons by simple thermal pre-treatment. The treated Vulcan and Ketjenblack substrates have a specific surface area of 322 and 1631 m(2) g(-1), respectively, instead of 262 and 1102 m(2) g(-1) for the as-received materials, which is a 23 and 48% improvement. Subsequently, when used as platinum nanoparticle (3 nm) supports, the electrochemical active surface area is enhanced by factors of 2.2 and 1.2 for treated Vulcan and Ketjenblack carbons, respectively. Furthermore, electrochemical investigations have highlighted a surprisingly improved catalytic activity for the pre-treated Vulcan XC 72R and Ketjenblack EC-600JD supported Pt nanoparticles. In fact, the synthesized nanostructures from the so-called "Bromide Anion Exchange" method exhibit good catalytic activity toward glucose electrooxidation, both in the alkaline medium and the phosphate buffered solution at pH 7.4. More importantly, the present catalysts are four times more active than those in the literature prepared under similar conditions for glucose dehydrogenation at low potential (0.27 V vs. Reversible Hydrogen Electrode). Consequently, these remarkable trends uncovered herein provide ample new strategic routes for the pre-treatment of Vulcan XC 72R and Ketjenblack carbons for widespread uses.

Recent Advances in Carbon Supported Metal Nanoparticles Preparation for Oxygen Reduction Reaction in Low Temperature Fuel Cells

“…Thus, the partial or total substitution of Cl − by bromide anions must accentuate steric hindrance around the metal cation, which will further play a crucial role during the seed's growth. This advanced method has been successfully used to synthesize Au-based nanocatalysts for glucose electro-oxidation [38,57], Pd-based electrocatalysts for glycerol electro-oxidation [36,37,101] and hybrid/abiotic electrodes for biofuel cell application [102,103]. This convenient and straightforward synthesis approach is an environmentally friendly method and is based on the use of bromide ion as a capping agent, the major gate in the BAE process.…”

“…In order to have a good dispersion of nanoparticles, conducting and high surface area (BET surface) carbon substrates are currently used. The main roles of the support are to improve nanoparticles dissemination, to reduce the metal content (generally noble metals are used) and to provide good nanoparticles-support interactions [53,54,57]. Vulcan XC 72 and Vulcan XC 72R carbons are the most used substrates for electrocatalytic applications and the metal content rises from 20-40 wt.%.…”

“…Vulcan XC 72 and Vulcan XC 72R carbons are the most used substrates for electrocatalytic applications and the metal content rises from 20-40 wt.%. For this purpose, Vulcan carbon is thermally pre-treated (see Section 2.4) to remove the potential undesired contaminants coming from its industrial manufacture such as sulfur [53,54,57,58]. Very recently, it has been shown that this thermal activation highly improved the physicochemical and electrocatalytic properties of Vulcan [57].…”

“…For this purpose, Vulcan carbon is thermally pre-treated (see Section 2.4) to remove the potential undesired contaminants coming from its industrial manufacture such as sulfur [53,54,57,58]. Very recently, it has been shown that this thermal activation highly improved the physicochemical and electrocatalytic properties of Vulcan [57]. We will briefly describe herein a typical synthesis as currently carried out in our research group, from two microemulsions: one containing the dissolved metal(s) precursor(s) and the other one, the reducing agent, NaBH4.…”

Electrocatalytic and Electroanalytic Investigation of Carbohydrates Oxidation on Gold-Based Nanocatalysts in Alkaline and Neutral pHs

“…41 The anion exchange membrane (AEM) was purchased from Fumatech (Fumasep FAA) and activated by soaking in 0.1 M NaOH overnight (2 h in 1 M NaOH is fine). Carbon Paper (Spectracarb 2050L-1050) was purchased from Fuel Cell Store.…”