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

Abstract

The high mass and volume-specific energy of dimethyl ether (DME) relative to hydrogen make it an attractive alternative electrochemical fuel source for portable applications such as powering drones and eVTOLs. A key stumbling block to the development of direct DME fuel cells (DDMEFCs) is the poisoning of the electrocatalyst surface by oxidation intermediates such as CO ads . In this study, an all-queous colloidal synthesis method for producing highly dispersed Pt 2 Bi alloy nanoplatelets (NPT) to mitigate such poisoning is presented. NPT synthesis entails the use of stannous chloride as an autocatalytic reducing and stabilizing agent for both Pt and Bi salts in aqueous solution. Sn and Bi stripping from the surface of these NPT is found to maximize activity for DME electrooxidation (DMEOR) relative to commercial Pt-C. A stable chronoamperometric current of 3.3 A g Pt −1 (15.8 μA cm Pt −2 ) is observed at the peak CO ads -stripping potential of 0.7 V vs RHE at 50 °C over a time interval where Pt-C activity becomes negligible. The response of anodic peak positions to potential sweep rates is used to reveal the impact of alloying (electronic structure) on the electro-oxidation rates of various intermediate species on Pt 2 Bi NPT. Resistance to poisoning coincides both with a reduction in the C ads specific activity onset potential by 25 mV relative to Pt-C and faster DME electro-oxidation kinetics. DDMEFC testing of the unsupported Pt 2 Bi NPT utilizing a phosphoric acid-doped polybenzimidazole (PBI) membrane operating at 240 °C yields a peak power of 56 W g PGM,anode −1. This represents a 30% increase relative to a commercial PtRu catalyst.

Nonthermal Plasma‐Modified Carbon‐Carrying Sn‐Based Ternary Nanocatalyst for High‐Performance Direct Dimethyl Ether Fuel Cells

“…This is attributed to the anodic current yield due to the oxidation of the DME molecules adsorbed during the reverse scan between 0.8 and 0.7 V. In the anodic potential scan, DME oxidation begins at around 0.50–0.58 V, depicting two peaks in the range of 0.72–0.78 V. Earlier reports on DME electro‐oxidation on Pt‐based catalysts ascribed these two peaks to the sequential oxidation of CO ads and CHO ads . [ 41 ] Beyond 0.8 V, the formation of surface oxides leads to the rapid decline of the curves. [ 40 ] During the reverse scan, the highest anodic current was obtained by Pt 3 Pd 3 Sn 2 /A‐MWCNT.…”

Intermetallic PtTe metallene for formic acid oxidation assisted electrocatalytic nitrate reduction

“…The Pt 0 4f 7/2 binding energy of PtTe-ML is located at 71.55 eV (Figure 1c between Pt and Te in the PtTe intermetallic compound. [33,44,45] Transmission electron microscopy (TEM) image shows that PtTe-ML has a typical 2D sheet structure (Figure 2a). The control experiments show that PVP plays an important role in the morphology control of PtTe, which ensures the formation of ultra-thin 2D structure (Figures S3).…”

Chemical-Dealloying-Derived PtPdPb-Based Multimetallic Nanoparticles: Dimethyl Ether Electrocatalysis and Fuel Cell Application

“…Dimethyl ether (DME)-fueled polymer electrolyte membrane fuel cells (PEMFCs) are of growing interest owing to the various advantages that DME could offer as compared to those with hydrogen and widely investigated liquid fuels, including methanol (MeOH) and ethanol. 1 DME has a higher volumetric energy density (20 MJ/L) than that of hydrogen (4.5 MJ/L). Its ease of storage and transportation overcomes the high-pressure requirement of hydrogen as DME can be liquified under a relatively low pressure of 0.5 MPa.…”