Pt/Tin Oxide/Carbon Nanocomposites as Promising Oxygen Reduction Electrocatalyst with Improved Stability and Activity

Enhanced performance of proton exchange membrane fuel cells by Pt/carbon/antimony-doped tin dioxide triple-junction catalyst

A composite material comprising carbon black and Sb-doped SnO2 (ATO) is employed as a support for a Pt catalyst in a membrane electrode assembly (MEA) to improve the performance of a proton-exchange membrane fuel cell under low-humidity conditions. The effects of Sb-doping on the crystal, structural, and electrochemical characteristics of ATO particles are being examined. In a single cell test, the ratio of Sb in ATO is systematically optimized to improve performance. The distribution of Pt nanoparticles is uniform on carbon black and ATO carrier, forming notable triple-junction points at the interface of carbon black and ATO carrier. This structure thus induces a strong interaction between Pt and ATO, promoting the content of metallic Pt. Compared with a Pt/C catalyst, the best-performing Pt/C-ATO catalyst exhibits superior electrochemical activity, stability, and CO tolerance. The power density of MEA with the Pt/C-ATO catalyst is 15% higher than that of the MEA with the Pt/C catalyst.

Highly Durable PtNi Alloy on Sb-Doped SnO2 for Oxygen Reduction Reaction with Strong Metal-Support Interaction

Carbon-supported Pt is currently used as catalyst for oxygen reduction reaction (ORR) in fuel cells but is handicapped by carbon corrosion at high potential. Herein, a stable PtNi/SnO2 interface structure has been designed and achieved by a two-step solvothermal method. The robust and conductive Sb-doped SnO2 supports provide sufficient surfaces to confine PtNi alloy. Moreover, PtNi/Sb0.11 SnO2 presents a more strongly coupled Pt-SnO2 interface with lattice overlap of Pt (111) and SnO2 (110), together with enhanced electron transfer from SnO2 to Pt. Therefore, PtNi/Sb0.11 SnO2 exhibits a high catalytic activity for ORR with a half-wave potential of 0.860 V versus reversible hydrogen electrode (RHE) and a mass activity of 166.2 mA mgPt -1 @0.9 V in 0.1 M HClO4 electrolyte. Importantly, accelerated degradation testing (ADT) further identify the inhibition of support corrosion and agglomeration of Pt-based active nanoparticles in PtNi/Sb0.11 SnO2 . This work highlights the significant importance of modulating metal-support interactions for improving the catalytic activity and durability of electrocatalysts.

Carbon-Supported Pt-SnO2 Catalysts for Oxygen Reduction Reaction over a Wide Temperature Range: Rotating Disk Electrode Study

Pt/C and Pt/x-SnO2/C catalysts (where x is mass content of SnO2) were synthesized using a polyol method. Their kinetic properties towards oxygen reduction reaction were studied by a rotating disk electrode (RDE) technique in a temperature range from 1 to 50 °C. The SnO2 content of catalyst samples was 5 and 10 wt.%. A quick evaluation of the catalyst activity, electrochemical behavior and average number of transferred electrons were performed using the RDE technique. It has been shown that the use of x-SnO2 (through modification of the carbon support) in a binary system together with Pt does not reduce the catalyst activity in the temperature range of 1–30 °C. The temperature rising up to 50 °C resulted in composite catalyst activity reduction at about 30%.

Ordered SnO2@C Flake Array as Catalyst Support for Improved Electrocatalytic Activity and Cathode Durability in PEMFCs

Pt-SnO2@C-ordered flake array was developed on carbon paper (CP) as an integrated cathode for proton exchange membrane fuel cell through a facile hydrothermal method. In the integrated cathode, Pt nanoparticles were deposited uniformly with a small particle size on the SnO2@C/CP support. Electrochemical impedance spectroscopy analysis revealed lower impedance in a potential range of 0.3-0.5 V for the ordered electrode structure. An electrochemically active surface area and oxygen reduction peak potential determined by cyclic voltammetry measurement verified the synergistic effect between Pt and SnO2, which enhanced the electrochemical catalytic activity. Besides, compared with the commercial carbon-supported Pt catalyst, the as-developed SnO2@C/CP-supported Pt catalyst demonstrated better stability, most likely due to the positive interaction between SnO2 and the carbon coating layer.

On the Influence of Composition and Structure of Carbon-Supported Pt-SnO2 Hetero-Clusters onto Their Electrocatalytic Activity and Durability in PEMFC

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current–voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

Strong metal–support interaction improves activity and stability of Pt electrocatalysts on doped metal oxides

Niobium and antimony doped tin oxide loose-tubes decorated with Pt nanoparticles present outstanding mass activity and stability, exceeding those of a reference carbon-based electrocatalyst.

Platinum nanocatalysts on metal oxide based supports for low temperature fuel cell applications

In this manuscript a survey of the contemporary research related to platinum nanocatalysts on metal oxide based supports for low temperature fuel cell applications is presented.

Tin dioxide facilitated truncated octahedral Pt3Ni alloy catalyst: synthesis and ultra highly active and durable electrocatalysts for oxygen reduction reaction

This work firstly synthesized SnO₂ modified truncated octahedral Pt₃Ni alloy nanoparticle electrocatalyst using neat FPD as the solvent, ORR activity and durability of which is 2.4 times and 2.5 times that of Pt₃Ni catalysts.

Electrochemical stability and postmortem studies of Pt/SiC catalysts for polymer electrolyte membrane fuel cells

In the presented work, the electrochemical stability of platinized silicon carbide is studied. Postmortem transmission electron microscopy and X-ray photoelectron spectroscopy were used to document the change in the morphology and structure upon potential cycling of Pt/SiC catalysts. Two different potential cycle aging tests were used in order to accelerate the support corrosion, simulating start-up/shutdown and load cycling. On the basis of the results, we draw two main conclusions. First, platinized silicon carbide exhibits improved electrochemical stability over platinized active carbons. Second, silicon carbide undergoes at least mild oxidation if not even silicon leaching.

Highly effective oxygen reduction activity and durability of antimony-doped tin oxide modified PtPd/C electrocatalysts

The oxygen reduction reaction activity and stability of PtPd/C are promoted by introduction of antimony-doped tin oxide in the support.