Dimethyl Ether Oxidation on an Active SnO₂/Pt/C Catalyst for High‐Power Fuel Cells

Abstract

Dimethyl ether (DME) has been considered a potential fuel for direct-feed proton exchange membrane fuel cells, owing to its high energy density, low toxicity, and low crossover through a Nafion® membrane in comparison to commonly reported fuels such as methanol, ethanol, and formic acid. The main hurdle in the implementation of direct DME fuel cells is the sluggish oxidation kinetics on state-of-the-art PtÀ based catalysts (e. g. Pt and PtRu). In this work, DME oxidation on a platinum-coated tin oxide catalyst (Pt/SnO 2 ) supported on carbon is reported and compared with commercial Pt/C catalysts. Our catalyst was synthesized by using the polyol method, and structural characterization was performed by using transmission electron microscopy and X-ray diffraction. Electrochemical analysis in acid solution showed overpotentials that are 50 mV lower than commercial Pt/C, as well as a higher oxidation current ( 44 mA À 1 Pt ). The peak power obtained using a 4 cm 2 laboratory prototype fuel cell (loading of 1.23 mg Pt cm À 2 on anode at 0.40 V) was 105 mW cm À 2 at 70°C. Online mass spectrometry analysis of the oxidation products gives insights into the new pathways of the electro-oxidation mechanism on this promising catalyst.

Aqueous Synthesis of Highly Dispersed Pt2Bi Alloy Nanoplatelets for Dimethyl Ether Electro-Oxidation

“…This is labeled as Peak 1 in Figure , while the second peak in the doublet is labeled as Peak 2. Previous investigations suggest that this doublet arises from the successive oxidation of CO ads and CHO ads or reorientation of a bisulfite adlayer on different crystal facets of the Pt catalyst surface . We investigated the impact of a bisulfite layer by repeating DME electro-oxidation measurements in the DME-saturated, 0.1 M HClO 4 electrolyte.…”

“…Manipulation of the salt reduction/precipitation approach used in the syntheses of these NPs and the introduction of a tertiary component such as Pd , on carbon-supported NPs or Cu as an alternative to Ru to form unsupported NPs have been shown to improve DME electro-oxidation activity relative to Ru alone at lower overpotentials. More recent work with novel Pt and Pt x Pd y -mixed metals on tin oxide support demonstrates the highest low-temperature DDMEFC peak power obtained to date (110 mW cm –2 at 0.4 V vs RHE and a loading of 1.2 mg PGM cm –2 at 70 °C). , The highest mass-specific chronoamperometric current reported for these materials is about 2 A g PGM –1 (4.44 μA cm Pt –2 ) for up to 1.6 h at 0.6 V vs RHE in DME-saturated 1 M H 2 SO 4 at 40 °C. Our fundamental exploration of highly dispersed Pt 2 Bi NPT is motivated by the ongoing need for new electrocatalyst synthesis strategies to enhance DMEOR activity.…”

“…More recent work with novel Pt and Pt x Pd y -mixed metals on tin oxide support demonstrates the highest low-temperature DDMEFC peak power obtained to date (110 mW cm −2 at 0.4 V vs RHE and a loading of 1.2 mg PGM cm −2 at 70 °C). 30,31 The highest mass-specific chronoamperometric current reported for these materials is about 2 A g PGM −1 (4.44 μA cm Pt −2…”

“…These findings are summarized in Table . A comparable table for low-temperature DDMEFCs has recently been published …”

Ultrafine Pt nanoparticles supported on double-shelled C/TiO2 hollow spheres material as highly efficient methanol oxidation catalysts

“…Furthermore, the CO poisoning effect on the catalysts is a big problem. To reduce the dependence on precious metal and avoid the poisoning effect, catalyst supports consisting of carbon materials [7 , 8] and transition metal oxides (SiO 2 [9 , 10] , SnO 2 [11] , TiO 2 [12][13][14] , CeO 2 [15] are extensively studied. Among them, oxides play a critical role owing to their charge transfer phenomena [16] and the ability to inhibit the dissolution of Pt [17] .…”